There are some highly noteworthy exceptions to your statement. You might want to google the "Three Hundred Degree Club" to learn about some of the superb insulating properties of water.

Unfortunately (or fortunately, depending on your point of view), you'll have to winter at the South Pole station to join. Very exclusive membership in this club... <img src="/images/graemlins/grin.gif" alt="" /> (No, I'm not a member, but I certainly would wear a sock if I were joining.)