It's like how on certain days some people wear sweaters when other people can wear t-shirts and still feel comfortable - different reactions to the same temperature.
Grace: I picked up my sweater from the floor and crawled back into bed. Shoving my pillow aside, I balled up the sweater to use instead. I fell asleep to the scent of my wolf. Pine needles, cold rain, earthy perfume, coarse bristles on my face. It was almost like he was there.