NO THANK YOU: How To Enjoy The Cold: Advice From An Arctic SCUBA Diver. I dove (on Cayman) with a fire chief from Calgary and his lovely wife a few years back, and they were extolling the virtues of ice diving. They cut a hole in the ice on a lake, and put a bunch of lanterns around it so you can find it on the way up, and then dive. I’m sure it’s lovely, but I’m more a tropical type. My regulator is certified for Arctic temperatures, but I very much doubt I’ll ever put that to the test.

On the other hand, I used to have a Russian friend who said that the problem is never that it’s too cold — it’s that you aren’t dressed warmly enough. I embrace that.