How do you say hot chick in spanish?

!El es caliente!, or you could say chico caliente or if it's a girl chica caliente.

Also here we use the Word "hot" in the middle of a Spanish sentence, or its translation "caliente", with both the meaning of sexually attractive or attracted. You may hear "¡Qué caliente que está ese pibe!" (How hot that guy is!) or mina (girl, but it's quite vulgar), but even most used: "¡Qué bueno que estás!" (literally "how good you are!", meaning "you look very good" or "you're hot")