I've been watching Big Bang Theory since it's been in syndication, so not too long.
The costum designer seems to be a bit stuck. They always wear the same thing; Raj always wears a jacket, swater, shirt, tshirt, Lenny always in a jacket, hoodie, and shirt. Howard always a shirt over a turtleneck swater. and sheldon a tee shirt over a long sleeve tshirt.
I thought they live in Pasadena California, pretty warm there isn't it?
Just a thought