Anything under 60 degrees is cool. That is when humans start being uncomfortable naked due to temperature.
Anything under 30 degrees is cold, which is when one layer of clothes stops being comfortable.
Anything under 0 degrees is very cold, when two layers stops being comfortable.
Anything over 90 is hot, when 0 layers stops being comfortable.
Temperature is only complicated if we want the sun's perspective, but since he is a jerk who will give me cancer I don't.