Now that I'm in my 40's, 30*F or so will make me not even think about going skating. Usually ice and snow is a bigger deterrent than temp. In my 20's though it was very common to find a parking garage, sweep it out and session with friends until 1:00-2:00 in the morning regardless of temperature. You'd start off bundled up and and freezing. But after a while, you would get hot and it was down to t-shirts and pants. Steam billowing off of every inch of exposed skin. Have some great memories of those sessions because I think everyone that was there was focused because of the conditions we were dealing with. Anyway, to answer the op's question... 30*s turns me into a chump these days.