If you have the hots for someone, you want them in a sexual way — you find them very attractive, and it is the body talking, not only liking their personality. English speakers do not say this as a simple verb to hots; they use the noun in that set phrase, have the hots for. It is informal, a bit teenage, a bit gossip-y, and a bit old-fashioned now; younger people may say they fancy someone, they are into someone, or they have a crush, which can be softer. The hots is stronger and more physical than a shy crush. You would not use it in a formal essay, or about a child's feelings. Though actually, it can be half-joking among friends, and it is usually about a person, not a thing.