Lol... i found this topic rather amusing because I live in Singapore (points if you know where it is). And over here it is unbelievably hot and humid. All year. Conducting science experiments at "room temperature" here involves adding ice to tap water to bring it down from 33 degrees celsius.
Anyway, at these temperatures you wouldn't think I'd need to keep my hands warm, but..... as it turns out, the whole friggin' country has some sort of a fetish for unbelievably cold air-conditioning... which totally freezes me out. I normally just try to stand OUTSIDE in the sun... which helps. If that's difficult, I'll warm them up by sitting on them, hot hand-dryers, wiggling, etc. I make it a point never to use water... because it gets warm, and then it evaporates and gets cold again... which quite defeats the purpose.