Actors In Water : How Long Is Safe?

At this moment I'm working on a shoot where the actors (two young women) have to go into the water for some time. At the moment the water of coastal NSW (that's Australia), is a meagre 16°Celsius. Are there any online resources where I could find a table on how long keeping them in water is safe (probably based on body weight, water temperature, air temperature?).

What do you maintain as general guideline (besides "as short as possible" of course).

Cheers

Martin Heffels

Filmmaker/DP/editor,

Sydney, Australia

"Today's mighty oak is just yesterday's nut that held its ground."

Martin Heffels wrote :

>At this moment I'm working on a shoot where the actors (two young >women) have to go into the water for some time. At the moment the >water of coastal NSW (that's Australia), is a meagre 16°Celsius.

I'm sure it must be in your script that the women should look blue, chattering teeth like demented squirrels, are generally miserable and covered by gooseflesh?

In that case, throw them back in until they quit on you. Can't you wait till summer? Say, December or January?

Robert Rouveroy csc

The Hague, Holland

I plan to live forever. So far, so good.

>...is a meagre 16°Celsius. Are there any online resources where I could >find a table on how long keeping them in water is safe (probably based >on body weight, water temperature, air temperature?).

Your best source would be the American Air force who inherited (confiscated?) Dr Mengele's research on how long pilots would survive in the sea by putting Jews into tubs filled with ice-water until they died. His figures are deemed most accurate and are used by most Air Forces around the world.

Try your own Air force, why don't you?.

Robert Rouveroy csc

The Hague, Holland

I plan to live forever. So far, so good.

Martin Heffels wrote :

>At this moment I'm working on a shoot where the actors (two young >women) have to go into the water for some time.

Then you better have them sign a waver saying you are not liable if they suffer hypothermia or death AND have a trained EMT on the scene. Cold water is defined as being less than 21.1°C (70F) but this could vary in each case due to specific physical conditions of individuals. At or below that temperature there is a real possibility of reducing the core temperature of a person who is submerged for lengths of time to the point of unconsciousness or worse. The rule here is a person will survive 50 minutes at fifty degrees. I said 'survive'. I didn't mention what happens after ten, 20 or thirty. 50 minute represents loss of consciousness. Cramps are the first sign of a problem. Interesting fact is the less you move around in cold water the better your chances for survival. In water survival class they used to teach us about H.E.L.P. (Heat Escape Lessening Posture). It means staying in a position where you protect the groin by keeping the legs closed and keeping your arms against your side, both critical heat loss areas. It only works with a life jacket though.

At the temperatures you speak of you probably have less problems of hypothermia and a greater risk of pulmonary problems or coagulation of the blood. It's not so much being in the water, but the dangers of warming up a body that is exposed to cold water for long periods of time. So your actors might do great in the water for 20 minutes but die when they get out because everyone is rushing to warm them up, but is doing it improperly. That process has to be done very carefully.

NEVER MASSAGE THE ARMS AND LEGS OF A PERSON THAT HAS BEEN EXPOSED TO COLD WATER FOR LONG PERIODS OF TIME. YOU CAN MASSAGE THE TORSO.

You could cause a heart failure doing so because you are sending colder blood back into the body unnaturally. I also remember that diving into water that is 15°C and below has caused cardiac arrest in the past so you can't just dive into cold water either.

Sounds like you might be jeopardizing your actors health if you did such a thing. No human is alike. One could die very easily from an underlying health problem that no one is aware of while everyone else is fine.

Walter Graff

NYC

Do not underestimate cold water. 2 Years ago we filmed an actor on Malibu pier and I think it was no later than March. Pacific here's still fairly cold, somewhere in the mid-to-high 60's Fahrenheit. Script & Actor's role prevented wearing a wet suit.

When we prepped for the scene, I spoke to everyone about how cold this actor would be (I've gotten chilled in a 5mm wet suit here) People figure that mid-60's not too much colder than room temp, so how bad can it be? Real bad.

Production/Casting told the actor it would be cold - made sure they were ok with this, also a strong swimmer and in excellent condition. And we obviously chose to do it as quick as possible, and in the afternoon when the water might be one degree warmer than the cold mornings. EMT's and water safety nearby (this production would've done this even in warmer water - they were very thorough).

I think everyone was genuinely surprised in how little time cramps and shivering came into play - in under 15 minutes he had to come out since he could no longer reliably tread water. But it was plenty of time to shoot his coverage. Once you shiver uncontrollably its bad news whether its in the water or in the snow. And there was no warming him up for another take - he was done for the day.

Mark Doering-Powell

LA based DP

There are well documented stages of hypothermia, You can look at the Nazi data, but they were killing people trying to find out how long a downed flyer would last in the Baltic or Nth Atlantic. The University Wisconsin or Minnesota at Duluth has done extensive hypothermia research. I did a shoot there once with one of the researchers.

One land mark in hypothermia I recall is that as core temp drops to between 95 & 93 degrees the ability of the person to do simple math problems like addition and subtraction decreases dramatically. Researchers used to ask a series of math questions of subjects immersed in the cold tank and this effect of the cold on the ability to do math was discovered. Of course they also had temp probes in their subjects so they could correlate at what temperature the effect kicked in.

Mark Smith DP

Oh Seven Films Inc.

I see a certain risk there.

From my experience as a scuba diver I know that as soon as the water temperature is lower then our body's temperature (37°C?) even by a few degrees, there is some form, more or less acute, of hypothermia taking place. Water conducts and disperses heat or cold several times faster then air. 16°C will seem quite cold in a very short time. Consulting local diving/safety experts would be wise but their opinion is likely to be similar to the ones expressed in this and previous postings.

Have you considered suiting them up in wet or dry suits? Might not be easy to conceal however depends on the action. I routinely spend close to an hour in 3-4°C water with very negligible ill effects properly suited up.

Perhaps a few quick wide shots with stunts doubles and cheat the CU's in a controlled and warmer water tank or pool. Anything to avoid spending much time in the real ocean water.

Good luck

Daniel Villeneuve, c.s.c.

Directeur-Photo/Director of Photography

Montréal, Canada

http://pages.infinit.net/davil

Daniel Villeneuve wrote:

>Have you considered suiting them up in wet or dry suits? Might not be >easy to conceal however depends on the action. I routinely spend close >to an hour in 3-4°C water with very negligible ill effects properly suited >up.

~~~It worked on "The Hunley" a segment of "The Great Adventure". Jackie Cooper, James MacArthur and myself were in a very cold tank in the winter for hours in wet suits with long johns over with no ill effects. Since most of the wardrobe is under the water I see no reason not to wear wet or dry suits. I for one would never get in killer water without one.

David Macklin

ACTING In The Motion Picture BUSINESS

http://www.davidmacklin.com

16 ° C=60.8 ° F - is very cold without a wetsuit, dry suit or warm water plumbing.You can find lots of charts on the net, but most of those have to do with SURVIVAL, not performance.

I have experience in the performance end. I asked a paramedic this just now, i.e. "How long should a crew keep an actor, a good swimmer, in good shape with average body-fat, in the water for a take?"

The answer : "Without a wetsuit? - 5 minutes, tops."

I'm a diver, a white water enthusiast and I've done gold dredging in California snow fed rivers. After five minutes your actor would experience a significant change in metabolism. His or her acting would suck after 5mins anyway.

A risk you need to consider is hypothermia causing shock that triggers heart failure. We had a white water death caused by this in Wisconsin this year. If the lower body's out of view, you could have them wear white water dry pants, such as these from North West River supply :

http://www.nrscatalog.com/product.asp?pfid=2586

I paddle with a dry top only and it works pretty well. You could also cover their mid-body, feet, or whatever else is out of frame, with neoprene (which you can buy from NRS or other white water outfitters).

For very long exposures when gold dredging, one trick is to hook up a warm water tube from a pump on shore, run that down into a diver's suit. Some cold water divers stay down for hours this way.

To warm up between takes the best way to deal with hypothermia is to have the subject walk/run to get their own body heating itself up inside out. If the actor is too cold to run around, they're too cold to continue with another take.

Michael Poimboeuf

Section Manager, SMPTE SF Section

Consulting Engineer Avid/Digidesign

Thank you all for your kind responses.

Indeed, acting is far different from survival.

We used wetsuits already from the beginning, covering up to chest, but still the talent was very cold. Ah well, maybe she was a "cold" person to start with. We tried to stick as much as possible to the 5 minute rule, and this helped, but if one has to plunge in the cold water several times for 5 minutes, in the end, they get cold anyway.

Cheers

Martin Heffels

Filmmaker/DP/editor,
Sydney, Australia

"Today's mighty oak is just yesterday's nut that held its ground."