A couple players rolled up to "the spot" the other night on new bikes, but only wearing helmets, gloves and t-shirts...
I asked one of them why he wasn't wearing a jacket and he replied, "I'm not cold."
Right, you might not be cold but that's not really the point of wearing protective gear. You could wear three hoodies to protect against cold air, but they won't be very effective when your shoulder meets the pavement.
We're not in Florida where it's 100,000 degrees either; it was about 65 out—perfect jacket weather!