it was cold at college and he noticed your unwarm clothes, you were just wearing a t-shirt and a skirt, he decided to lend you his big white hoodie so when you returned it, your scent would be there and he could smell you indirectly, and that would make him more comforted he enters the library you were in, and he gives you his hoodie

"wear this, it's cold today"

as you grab the hoodie he goes back to his classroom