I own all the seasons and I used to put them on in the background, so I’ve seen all of them at least 3 times.
As the others have noted, the only related episode is the Titanic episode, with James Cameron.
Effectively, what they test is how quickly hypothermia takes effect, in water and in air, which they have tuned to match what the conditions would have been that night.
To do this, they build a ballistics gelatin figure of a human with a circulatory system inside of it, with fluid (water - taking the place of blood) running through the pipes, that comes out the top of the head. A small heater attempts to keeps the circulating fluid warm, at about the same ability as the human body has to keep itself warm, before recirculating it back into and through the body.
They cloth the body and put it into a bath of icy water and time how long it takes for the body’s core temperature to drop to fatal levels.
They warm the body back up, dunk it into the ice water, then raise it onto a plank above the icy water into the chill air and again time how long it takes for the core temperature to drop to fatal levels.
Using historic research, they know how long the people had to be able to survive to be discovered and determine that it’s plausible that a person on a plank above the water could have been discovered just before they would have died.
A person in the water for the whole duration, no such luck. (I don’t remember this bit, but I believe that to be the case.)
Overall, not a bad test. Among their better, in a sense.
Some aspects where I think we could say that the test is only grossly applicable:
- The body they molded was a large, beefcake sort of guy. A smaller woman or a skinny lad like Leonardo di Caprio would, presumably, get cold faster.
- The average depth of the pipes in the body would be different from a human body.
- The overall materials and layering of materials between a human body and the figure would be very different (layers of fat over the body in some places vs. bone backing in others, etc.)
- When the body gets cold, it is able to restrict bloodflow to the limbs. The dummy figure is incapable of such a thing (though, the piping was probably not as extensive as the total human circulatory system, so it might not be so completely far off for the conditions it was modeling).
- The dummy was 100% out of the water while in Titanic the headboard that the girl was lying on was floating on had water coming up onto part of it, coming into contact with her legs and feet. This would have sapped heat out of her more quickly.
On the whole, I’d say that if you’re a large fellow and you can find something large enough to get you completely out of the water, then your chances of surviving would have been improved. But I think we can safely say that anyone who was able to move well in enough in the icy water, calmly-headed enough, would have certainly tried to make use of anything they could. I doubt that there’s anyone who, given sufficient presence of mind, wouldn’t have made the attempt to utilize whatever the boat was spitting out, so it’s a bit silly to say that “if the people had only tried getting on the flotsam…”
On the other hand, it may be conceivable that if the crew and captain had been more organized and creative, they could have lead construction of make-shift boats from tables and tarpaulin or who-knows-what. It looks like they had two hours.
Of course, this is before bungee cord and duct tape. Throwing something together may have been a lot more difficult back then.
