More than I expected. Might get a little warm in the Florida heat as it does retain heat very well. Absolutely water proof, and fashionable as well if you're a country boy. My dress shirt size is a 17 1/2 34/35 Large, I bought the XL size, of course bigger than needed, but easy to conceal full size pistols, knifes. Also in wet outdoor conditions I can fit my entire upper body in this, a cheap mosquito net for your eyes would be the only recommendation if you plan on sleeping in this. It cover all except visual. I'm 6'1 210.
These things work as expected. The intent is to keep your feet at body temperature. I just used these over the weekend on days where the temperature was ZERO... they worked. I like the fact there are no wires (I have ski boot heaters with wires and BIG batteries). The smartest way to use these insoles is to put them on medium to get the maximum time.