Why when I swim outdoors water first feels cold, and later warm?

[JerryM]

When I first enter the water it feels very cold and painful. But after few minutes it becomes very comfortable.

I know skin somehow adjusts to the temperature. But what does such adjustment mean? Does thermo-conductivity drop after a while so cold doesn't affect as much? How does this work?

Where can I read about this?

 

[lalala]

You get used to it! It's not really skin that adjusts. Skin only feels different versus not different. The reason your skin feels the temperature is not because it can tell cold or hot - it's in comparison to what you were. After a while, your body notices that your current temperature is no different than it was a few seconds ago, and that's how you're used to it. This is why only people who spend a lot of time in pools (swimmners like me) are good at guessing temperatures. We're in the pool so consistently that we learn what each temperature feels like in comparison to hot, cold, temperate, etc. Your average recreational swimmer is often surprised to hear that a pool that might feel cold has a higher temperature than the air.

It happens at indoor pools, too.