Plus, if you took off from somewhere cold (say, London) and then landed in somewhere warm (say, Istanbul), you are very likely to forget your coat.

ECONOMIST: Business travel

In one unusual but revealing study, his researchers repeatedly immersed one side of people's bodies until it showed evidence of habituation, while keeping the other side warm -- and then turned them over and immersed the side that had never been in the cold water and found that there was still a significant reduction in their cold shock response.

CNN: Are polar bear plunges good for you?