[pastrami_panda]

I'm not sure how being fully submerged for long periods of time affects this, but in outdoor culture there are sayings like "warm when wet" - pertaining to certain fabrics such as wool and polyester.

One famous strategy is the pile and pertex combination. Where you have a thin basically windproof but not waterproof shell made typically from Pertex, and then fake fur from polyster on the inside.

These jackets are used to (might still be) be worn by law enforcement to old school rock climbers for it's ability to keep you warm and damp for hours.

There are videos of people submerging in ice cold water and "walking it off" until they are damp but warm again.

Another saying is "cotton kills", because it does not provide warmth when wet and also sucks up insane amounts of water for its weight, so it bascially never dries out.

[jebarker]

I used to have a second hand, well-worn Buffalo Systems pullover and it was fantastic for staying warm whilst wet hiking.