If just because they tend to only use it when they feel like. Someone will touch their hand and say "Oh, you're cold" or they'll be invisible to thermal imaging or something... which wouldn't be so bad if so many people weren't so hot to passionately screw them any which where, how or why they've a want to. If it's really a cold dead (undead) body, then it's like kissing a latex covered store mannequin and fucking a vibrator fresh out of the refrigerator.