grolby

I'm from Massachusetts, a fair ways north of NJ if I recall correctly, and I follow it more or less.

I follow the 60 degree rule partly because I find it more comfortable and partly because it's good common sense. The knee isn't very well-supplied with blood flow under the best of circumstances. Whether your knee really will be more readily injured when cold, I'm not sure, but why take the chance? There's a tendency on the part of some people to underdress for the sake of seeming harder or something, I don't know. If leaving your knees bare at 50 degrees really is more comfortable, go for it I guess, but it doesn't make much sense to me.