Home of Professional Cinematography since 1996

Extreme Heat


I may be working a couple days in Death Valley shortly, and I'm looking for an overview of film and camera handling in temperatures around 120F, 20% humidity. I've checked the website (some good info about dealing with sand, but not so much about heat), and I've scoured every book I own for info about extreme heat. Lots of stuff about cold conditions, but not much about heat. I've shot in the desert several times so I'm pretty comfortable in dealing with sand, but these extremes of heat are new to me (for shooting at least).

Any general tips about keeping the film and camera cool? Coolers with sealed ice packs for the film? Anything better than a space blanket for the camera?

How about batteries? Details are still being worked out, but we will likely be using an SR3 or SR2. There will be a camera truck, but not much else. Of course my biggest concern is for the general health and safety of the crew, but then after that, having a successful shoot. Any general survival tips (that pertain to shooting) from those who've been there?

Thanks,

Michael Nash
DP/Pasadena, CA



I just got back from doing a week in Mojave, where the daytime highs were around 110° F in the shade, and of course there is no shade for as far as the eye can see. It is going to be hotter than that where you are going.

We used coolers with the blue ice packages to keep the film cool. They are the plastic containers with water inside that you freeze in your refrigerator ahead of time and then put in the cooler.

Do not use block or cube ice, as it will make the humidity in the cooler quite high and possibly even make the film itself wet.

We used magazine / camera covers that we fashioned out of space blanket with the shiny side out.

Make some covers out of the same material for the film / magazine coolers also.

You did not say what type of cameras you will be using, but you might encounter some thermal electronic problems that manifest themselves only when the camera becomes quite hot.

Take a spare camera body, or at least spare boards for the body you do take. Check often to be certain that the speed and shutter angle settings are still where you expect them to be. As you mentioned, sand is a problem.

I use large clear plastic trash can liners to make camera/lens covers.

We make a hole for the lens/mattebox, and hole for the eyepiece and then use a bungee to hold it tight closed around the bottom of the pan head.

Batteries operate well if used in the heat. Just be certain let any battery, particularly nickel-cadmium batteries cool off before you try to charge them.

The more sophisticated chargers have a temperature probe in the battery cell pack and will prohibit or limit charging if the cells are too hot.

Your most difficult problem is going to be the welfare of yourself and the crew.

Here are a couple of things I have learned over the years :

! )Dress in loose, light colored cotton long sleeved shirts and trousers.

2) Put sun block on every part of exposed skin, and re-apply often.

3) Wear a light colored wide brimmed hat to shade your head, face and neck.

4) Have a hat leash that connects your hat to your collar to keep it from blowing away.

5) A piece of string and an alligator clip in the back work well.

6) Wear sunglasses to prevent snow blindness in bright light colored surroundings.

7) They also help keep sand out of your eyes.

8) Drink water and electrolyte replacement fluids constantly.

That is so important I will say it again : Drink constantly!

Everyone should be walking around with a bottle in the hand or pocket, always drinking.

The air in the desert is so dry that you will not think you are sweating, but you are loosing moisture at such a rapid rate that by the time you are thirsty, it will be too late: you are by then well on your way toward heat exhaustion or even heat stroke.

Don't take this fact too lightly, you are heading into an environment that can and has killed people.

Things I have learned about what to drink in the desert :

1) Do not drink sodas, juices, alcohol, or anything else except 50% water and 50% electrolyte replacement fluids.

2) Do not drink ice cold liquids.

3) They will shock your system and you won't be able to drink enough of them.

4) The liquids should be cool, not cold.

Once I went down hard from the heat on a desert shoot, even though I was pounding down water. I learned from the doctor that saw me that it is absolutely vital to replace the salt and potassium that you have sweated out.

Once you deplete your body's supply of salt and potassium through sweating, you can drink all the water you want, but your body can't absorb it fast enough to keep up with your rapid rate of sweating without replacing the salt and potassium along with the water.

One of the absolutely best things we have found to replace the salt and potassium, better even than Gatorade or similar sport drink products, is Pedialyte. It is an oral electrolyte maintenance solution intended for infants, but works extremely well to rapidly rehydrate fully grown adults too.

We had production buying it or the store brand generic equivalent by the case and were drinking it every other bottle of water.

You find it in the infant food section of the grocery store. It comes in orange, grape, and cherry. There is also a non-flavored version, but it doesn't taste very good. The flavored kind taste like Cool Aid, so that's what we drank. We swore by it. We had 60 people out there in the desert, with no difficulties.

So, it is important to know: cool water alone is not enough, you must also drink at least 50 percent of your fluids in the form of an electrolyte replacement solution.Since you are going to such an extreme environment, I highly recommend that you take a trained nurse or studio emergency first aid person with you to look after everyone's welfare.

Don't let anyone wander off by themselves, off the beaten path. They might become hurt or lost and be in serious trouble before you notice they are gone and go to find them.

I also find it useful to wear a wet towel wrapped around my neck, it helps cool the blood flowing up into your head, and it great to wipe sand out of your eyes and off your hands. Because the air is so clean and clear in the desert, things will seem to be closer than they really are.

Resist the temptation to walk over to that nearby hill because it very well might be a couple miles away.

Be very careful, good luck, and give us a report when you return.

Bill Bennett Los Angeles


A very resourceful Afghanistan assistant once ('73) showed me how to keep exposed film reasonably cool during a trip through the desert in a Landrover. He packed the film cans in a blanket and tied it on the roof of the car. Temperatures were 45+c (that's about 115f to you, I think).


But he had fashioned a dribbler out of a rusty jerrycan he filled with 80% water and 20% gas that kept the blanket moist. I carried a thermometer in the First Aid box and I put them with the cans and sure enough, it worked well, temperatures were around 22c (72f) between the cans while driving. The evaporation was indeed a variation of how a fridge works. Nowadays everybody carries those coolers I suppose. You can get them run on 12volts.


The camera's? Use an umbrella of course. It is also a good idea to have the camera's checked for excessive grease: it melts sometimes, gucking up things. Nah. Shouldn't be a problem nowadays. Spage-age lubricants that keep their viscosity are normal now. We had to degrease our cameras when we shot in the Arctic, on the Dew line or else they'd jam!


Robert Rouveroy csc
The Hague, Holland



We used magazine / camera covers that we fashioned out of space blanket with the shiny side out.


This is common, but there's something you have to be careful of with this. Because you stick your eye into the eyepiece, you're using ND's (usually),and your eye opens up, sometimes quite a bit. Then you pull your eye awayand the full sunlight blasts down and bounces up off that shiny stuff andinto your unprotected eyeball!


I really messed my eyes up one day shooting on an ungodly hot day in Texas this way.

They swelled up and I couldn't focus them. It was really painful.I suppose you could actually go snowblind from this, where you literallysunburn your eyes.


So be careful. Open your camera eye slowly, or squint, immediately putsunglasses on, AND make those grips shade you with a 4X all the time!! :)
Another thing I used to do in Texas to stay cool is take off my shirt andsimply soak it in water, then put it back on. Cools your body right off fora good little while.

Phil "is that a wet T-shirt or are you happy to see me" Badger



I'd like to take this subject in a little different direction. I'm doing a project in Tampa, Florida (read lots o' sweat and fogging filters). Lets talk about the inside air-conditioned stage to the humid outer real world.

Any ideas on how to keep the filters from steaming. I know about silica gel and stuff and opening the cases as soon as you get outside and even taking them out early.
What about Nitrogen? I here that it is a drying gas? Hair dryers? Lots o' kim wipes?

Thanks
Michael Bratkowski



Bill Bennett wrote :

>Drink water and electrolyte replacement fluids constantly. That is so important I will >say it again: Drink constantly! Everyone should be walking around with a bottle in >the hand or pocket, always drinking. The health professionals say we should be >drinking eight glasses of water a day.

That's without the heat factor thrown in. As a recreational Mountain Biker I own a couple of (OK, four) of the many hydration systems I use the Camelback http://www.camelback.com/

It is a backpack or fannypack arrangement with a bladder that has a tube that comes over your shoulder and a bite valve that remains right near your mouth for quick and easy access. All of them have wide intake opening so ice can fit in them and of course you can put in whatever liquid you like. The different models have different size reservoir and different size backpack pouches a nooks for carrying other items for day trips. The advantage of wearing one while doing sports like snowboarding/skiing, running, biking is, you don't have to fumble down/around over etc. to get your bottle.


Apparently the US military uses these backpacks as studies show people definitely drink more fluids when outfitted with this type of water access. I wore one on my last outdoor shoot and it worked great when I couldn't get away from the camera. I've even taken to wearing my small one most of the time loaded with what day items I used to put in my fannypack. Trendsetter? I doubt it, but you could say, I'm all wet...


Eric Swenson
As they say in their ads, Hydrate or Die.

Usual disclaimers but I have thought about investing in them...


Bill Bennett wrote :


>Do not drink ice cold liquids. They will shock your system and you won't be able to >drink enough of them. The liquids should be cool, not cold.


Very good advice, that. I'll go one better!. If you can believe it, if you feel extremely hot, drink hot tea. You'll find you cool down very fast.


Robert Rouveroy csc
The Hague, Holland



We just did a shoot in some sand dunes about 1.5 hours north of Las Vegas. 116 degrees. I believe most Arri cameras are rated up to 122 degree fahrenheit. Strange that equipment has a temperature range but not people. Every summer sand dune shoot that I've been on has seen atleast two crew people going down. Sometimes so bad as to require hospitalization. Strangely it's never the director or producer that gets sick ....


We had an unexplained mysterious problem with two rolls of 5248. The first roll was O.K. and the four rolls shot after the two problem rolls were O.K., but the two problem rolls are so overexposed as to be unusable. We were shooting with two Arri 435's at the same time during which the problem occured. Both cameras used the same base exposure, slightly different filter packs.


The problem persisted with two different lenses, two different operators, two different AC's. No chance that the stop would have been left off for all of that footage.


The problem starts after a good take from earlier in the day on the one roll. Kodak examined the film and said that there were strange density marks around the perfs and edges of the film at the end of the last good take, that they thought indicated some type of mechanical problem. (?) Kodak determined that the film and processing were O.K. Overexposure was so bad that the frame lines were fuzzy from light bleeding around the gate!?


We think that the problem must have been heat related. When we used the problem camera again it had started to cool off and the next four rolls were O.K. again. The camera had been kept covered with a space blanket and in shade as much as possible but the intense heat just soaks in.


But the 435 is so sophisticated that it will shut down if it gets too hot (seen it happen) or the shutter is out of phase or not achieving the shutter setting that you have selected. (Shutter syncs within 1.5 frames of turning the camera on!)


Concering personal comfort. I find that the various SHARPER image personal cooling devices help, but others don't think they're worth much, at least not $50 worth. The hats with the built-in cooling fans work well for me. I try to keep a white hat on that I keep wet. Put ice cubes in your socks.


The Panavision stores are suppose to sell the large heavy duty clear bags.


They seem to be out of them often. If the wind is really blowing or the director wants the camera in the sand, production should be prepared to pay many thousands of dollars in repairs and cleaning costs. Taping over any openings in the camera helps. It's better to use a brush to clean things rather the using dust-off to blow dust and sand into the camera. If the wind is blowing the sand it's sometimes better not to check the gate.


Sometimes you have to change lenses and mags in a vehicle if the wind is blowing.
good luck!



Michael Bratkowski writes :

>...Lets talk about the inside air-conditioned stage to the humid outer real world. Any >ideas on how to keep the filters from steaming

Seems to me that if you're going from a stage to the hot/humid exterior you would have some control... You could have the temperature of the stage increased an hour before going outside. Use lamps to warm up gear - blondes work well. =46inally, plastic (clear) bag everything and get it outside as soon as possible. Once it has reached the exterior temperature you can remove the bags and there should be no unusual, or excessive, condensation. Lenses are the main thing to watch out for. Zooms in particular. You should allow at least an hour for a stone cold piece of gear going into a hot humid environment. And that means planning on getting enough kit warmed up so that you can still work while the cold stuff is warming up.


The worst of this situation I've seen is cold winter exterior to indoor pool. Now that's a move you wan't to think carefully about.


David Perrault



I have just finished 3 months in the desert in Morocco - last year another three weeks in the UAE, and as a fair-skinned red-head, I can categorically state that you have a MUCH better chance of survival with long sleeves and long pants than with the shorts & T shirt approach to desert garb. You are dealing with both radiant energy from the sun and reflected heat from below, and the combination can roast you and dehydrate you very fast. Not only are you sweating from the heat, but every breath you breathe out takes with it water vapor. I wear long sleeved cotton shirts and cotton rip-stop fatigues, a bandanna around my neck, and a wide brimmed hat. You can keep a wet bandanna on your neck - the evaporative cooling as it dries will cool you down nicely. Camping stores sell something called a Cactus Kooler which is a cotton tube filled with the same sort of crystals that are used in cleaning up hazmat spills. You soak this in cold water and it swells up.


During the day, the water against your neck keeps you cool. I highly recommend them. Use strong sunscreen. I actually use fingerless work-gloves because the backs of my hands burn easily ...and all metal things get very hot. If you look at the various desert cultures, may of theml swaddle themselves in voluminous robes - this helps keep a cooler microclimate near your skin by protecting you from the radiant heat that is bouncing up at you. I second Bill's plea to KEEP DRINKING.


We generally stuck to water with very occasional salt tablets - too much salt will do you in as easily as not enough. I have not used pedialyte, but it makes good sense. You can take a bed-sheet and sew it into a large bag that you can drop over the camera and AC to help keep the dust out during re-loads. It has the advantage over plastic stopping the dust but not sticking to the AC or steaming him/her. If you are in driving wind, tape everything up on the camera - light may not get into the box through the joints where the mag attaches to the camera, but dust might. 435s' electronic packages can get toasty - keeping sun off of the right side of the camera is a good thing to do. A Golf umbrella on a combo stand by camera is essential. We often mounted the umbrella right to the dolly.Keeping suncream from dripping into the corners of your eyes can be a problem. I use stick-type sunscreen on my face. Even if you never take off your hat, you can burn your face from the reflections. Black Pelican cases get VERY hot VERY fast. I use white pillow cases and slide my meter/filter/stills camera pelicans into them. It is a pain to slide them out every time that you need something, but, lets face it, the percentage of time that you actually need to get into the case is relatively small compared to the time that they are sitting around on set.


Make sure that your assistants know better than to wipe your filters too hard - fine silica dust is pretty much what they use in lapping compund or lens ginding compound. Wipe lightly. Some people spend hundreds of cans of air blowing off the camera all the time. Beware - you can drive dust into things as easily as off of them:-)
ALWAYS carry water...if you have a little water bottle on your belt or in your pocket, you will drink it...if it is over there somewhere, you will not want to take time away from what you are doing and can easily forget to keep drinking. You can buy little holsters for water bottles at any camping store - put one on your meter belt or wear cargo pocket pants and keep one on your leg ALL THE TIME.


As much as you would like to, DO NOT put freezing water or ice in your hat - over-cooling your head can confuse your body's ability to regulate heat. If you are schlepping gear long distances and breathing hard, drink more. Slow down and expect to get less work done than usual in the same amount of time. Don't drink too much coffee or tea.

Try to have fun

Mark H. Weingartner



Second the great post, Bill.


Just tried Pedialyte. Blech!

Goes down much better when you cut it with 50/50 water.
(The Berry flavor at least...) But I did feel a lot better (I'm out in Florida on the Gulf Coast, during the summer. Need I say more...). A lot better. So I'm sold. So far Wal-Mart has the generic for $2.77 per litre. I've had the Berry and I'm interested to see what the grape is like. Hope I'm not tooo far off topic.

Cheers,
Michael Bratkowski



Michael Bratkowski wrote :


>Lets talk about the inside air-conditioned stage to the humid outer real world. Any >ideas on how to keep the filters from steaming.

Best is to be patient. Wait a while, it'll go. Wiping and other gimmicks may just harm the coating. What's the rush? Same happens in the Arctic. Coming from outside to inside invarably fogs everything up. Good time to eat some blubber or partake of the Inuit's hospitality :^)

Robert Rouveroy csc
The Hague, Holland



Great post!

Glad that I read it before I responded as it saved me plenty of typing. (Was not aware of Pedialyte. Thanks.) As an aside, while I was shooting in the Sahara, the Egyptians on the crew insisted that I drink hot liquids (coffee, tea, etc.) in the desert as it would keep me cooler than cool drinks would. Sounded strange but they were all doing it. I started doing it (when in Rome...) and I could swear it worked (helped might be more like it. It was the Sahara afterall.).

Beware of ice buckets filled with Sea Breeze and kerchiefs...

M. Dietrick Schumacher
LA (and many a desert)/DP



Greetings,

Some tricks of me and some pals.


Sudden change or drop in temperature is more than often the cause of discomfort.


If you can regulate the AC (air conditioning, not the assistant) to slightly lower than the outside temperature one should feel the transition far more supportable, avoid a sudden sweating and also avoid catching a cold.


I also think for the gear a smooth transition must be better. Most important is to keep everything in the shade at all times and covered. I think the film must support better transition from cool box at around 20C, to mag at around 30C and then on the camera outside at + 40C. Rather then going from 10C to +40C in less than a minute. Please correct me if I am wrong.


Dresscode, rarely shorts. Hot tall legs rubbing on my sexy calf, no thanks. I tried the dishdasha, very good but not that practical. When very hot gloves highly recommended.


A good base ball cap in the spring or autumn, in the summer a nice panama less sticky and when really getting hot as in Kuwait or Saudi-Arabia, I strongly recommend the local hatta or headdress, especially in the desert. You can at the same time cover the ears and the neck. Of course sunglasses, preferably the mountaineering type with covered sides.

I also prefer hot drinks. A nice Turkish coffee, ouassad (medium sweet), at 05:00 AM when Temp is only 42C; later on once every now and then a nice cuppa local black tea. I also prefer standard mineral water, never cold but cooled slightly. Hot or cool drinks not only don`t affect the body temperature so much, a too cold drink can be deadly!, but also one drinks in a reasonnable quantity. Keeps the reserves going, particularly on unfamiliar and unfriendly grounds. And honestly I prefer a hot bottle of water than a hot Coke.


A nice little clear soup in the evening to compensate for dyhadration.
(Pesonally I prefer a gazpacho)


Too cold ingredients can also easily upset once stomach. In the event Imodium will cure your acute dia... you know what I mean. Around here Ice cubes most likely the cause for food poisoning. In the event Ercefuryl - an intestinal antibacterial agent. Needless to say I avoid ice cream, junk sweets and junk food. Dried food, especially fruit is quite nice. Also try olive tappenade (mashed olives) on bread; the roman legions use to speed around here on this. I have to admit that most of the time productions try to avoid these kind of shoots unless a specific effect is sought after or for a documentary shoot.


I sometimes don't understand those foreing productions who choose the worst possible time of the year to go and wonder in the desert or the mountains when it is not really justified. Too often I heard the excuse we didn`t know. They too often think it happens to the others.

Regards

Emmanuel Suys
Beirut

AC



This weekend I had the working lens and filter fog up after a 30 min. ride in a well air conditioned SUV (I never have that problem with my camera van). A quick fix (not without its own dangers) for slightly chilled glass surfaces is to use dust off to lightly blow the fog away- tape those fly away nozzles, test the stream before using on important glass surfaces, do not shake or move the can to aid in the process and stay far away and move in only slowly. I hate to even mention the dust off response but it can certainly pull you out of a jam when all hearts are intent on shooting. The other more painful solution for colder glass surfaces is to heat with solar or open face lights (again use all necessary precaution). If one prime from the box fogs up you would do yourself well to open the case and expose all front and back elements to the air. It sometimes helps to wipe away the gathered condensation with soft lens cloth during the warm up process.


Your better off if you can break away equipment to be used on an upcoming outdoors shot to a secure warm area (camera truck, non-ac lock up). As always keep the cases closed, two filter kits indoors and outdoors with the later remaining in the s.w.a., regular cleaning and maintenance a must and you may want to add contact cleaner for electronics and CRC 6-56 or similar lube for any corrosion that appears on exposed metal to your kit if it is not already there. And take heart, Tampa is very close to Florida's beaches and all the special pleasures of shooting there. Keep your rain covers close.


Best wishes,
David Campbell


The Egyptians on the crew insisted that I drink hot liquids (coffee, tea, etc.) in the desert as it would keep me cooler than cool drinks would. Sounded strange but they were all doing it. I started doing it (when in Rome...) and I could swear it worked (helped might be more like it. It was the Sahara afterall.).

I'm sure this is true, but it reminds me of the guy who liked to hit himself on the head with a hammer because it felt so good when he stopped! The 12v thermocouple coolers were mentioned. I tried one this year and was not impressed. It took forever to get sort of cool. In the desert I can't imagine it would be effective. OTOH, the chest is insulated, so I guess it would be better than a cooler with no ice bags in it.


Has anyone used these things in really hot temperatures?


Wade K. Ramsey, DP
Dept. of Cinema & Video Production
Bob Jones University


Wade Ramsey wrote :


>The 12v thermocouple coolers were mentioned. I tried one this year and was not >impressed. It took forever to get sort of cool. Has anyone used these things in really >hot temperatures?


Yes, and they work fine, as long as you don't expect it to make ice cubes. The good ones will make a 20 degree Centigrade43 difference between outside and inside temperatures, plenty to keep your film ok. They are used all over Africa to transport medicine. If you desire icecubes, why not go to any good maritime store and buy a gas operated fridge? They install them in small boats and they'll go forever on a good size propane tank. Around $200.- I think. And just once, just once, try sipping hot tea. You'll really, really find you cool off in no time. You think Berbers or other desert folk are stupid?


Robert Rouveroy csc
The Hague, Holland



IEmmanuel Suys wrote :


>I also prefer hot drinks. A nice Turkish coffee, ouassad (medium sweet), I think it >raises your body temperature enough that you don't notice the heat as much.

I think the heat still has the same effect on you though. Similar to taking a cold shower before going into a pool. The water will feel warmer when you get in. Also your body might use more energy drinking cold liquids then ones it has to heat to process. They tell dieting women to drink ice cold water because they burn some (probably negligable) calories drinking it.

I don't know if there is any truth to this. I heard also that putting something cool under the armpit will cool you fast because you are cooling the main artery thus lowering body temp. My pal Bob Collins swears by towels (similiar to the small ones you find in your hotel room) dipped in Seabreeze, water and ice and wrapped around the neck. Sez they used to bring them around to the crew in a pail.

Brian Girecky



Robert Rouveroy wrote

:
>If you desire icecubes, why not go to any good maritime store and buy a gas >operated fridge? They install them in small boats and they'll go forever on a good >size propane tank. Around $200.- I think.

That's a good idea Robert, Go to an RV store and get a used fridge, there are a few that work off of 120 V AC, 12 V DC, and Propane. Recently, when we were unable to freeze our Gel packs. The ice bags were leaking, and getting everything wet. So I ended up stuffing plastic water bottles full of ice chips. It helped, and they didn't leak.

Steven Gladstone
Gladstone Films



Not at all heat related, other than kinda' sorta'.


For those parts of the world infested with knats or black flies. (spring and early summer pests in many locations) Those toss-in-the-drier fabric softener sheets drapped out of the back of a hat will keep them away (from your face)...not to mention keep you smellin' fresh and cause everyone to ponder if they are missing out on a late-breaking fashion craze.

Cliff Hancuff
www.ClearDaySoftware.com



The other day someone posted a note that soaking Sea Breeze onto a rag and tying it around the neck was a good way to keep cool. I did this on a shoot in Death Valley where temps were in the 130° F range and I found it didn't work for me. The medic on the shoot was bringing around a bucket of water with sea breeze diluted in it. Initially upon putting the rag on my neck I felt the cool tingly sensation, but then I felt sick to my stomach a few minutes later and I took off the rag. At the time, I thought I felt sick because the smell of the Sea Breeze is so strong. After talking to another medic some time later, he suggested that the astringent effect of the Sea Breeze may actually hurt you because it closes the pores that need to be open to allow you to stay cool. I don't know which medic was right, but it didn't work for me.

Paul Szopa
DP - Los Angeles



...because it closes the pores that need to be open to allow you to stay cool.

>Returning to the hot drink part of this thread, I heard a BBC world service report talking about just this subject about 17 years ago, so the information should be right up to date. Taking in a hot drink encourages the pores to open and encourages perspiration, which is what keeps you cool. You have to replace to fluids of course. A mixture of the occasional coffee or tea, and a good deal of water, which should be at body temperature to be absorbed and used as quickly as possible is what I've found works best for me.

Sometimes space blanket hoods for me and the camera, but we weren't on fashion tips.


In addition to space blankets to protect equipment, I have heard that making awings, covers, or even tents from Roscoscrim or equivalent shiny perforated reflector works well. The idea is that with the shiny side out, most of the heat is reflected away and only 25% (according to the swatchbook) of the light is transmitted through. The holes also allow air to circulate better than a tent. Obviously, this rig is not the best to keep dust and sand out, but it does help with the heat.

Christopher B. Seivard