Cuddle bug:

A cuddle bug is a miniture virus like bug that infects people through cuddling. The effects slowly get more and more permanent and strongm its easily treatable with antibiotics.

Its effects are: -feeling cold when not touching someone -need to lay down -sluggish and sleepy -feeling warm happy and content when cuddling with someone -being very affectionate and needy -potentially getting aggressive is snuggling partner is taken away from them.