Pétard means firecracker in French. In Québec however, it may mean that or "stud." I guess "hottie" would be more appropriate as it relates to fire -- hot. It definitely has to be a guy though.

Patrice est un pétard.
Patrice is a hottie.

Note that pétard comes from "péter" which means "to explode", but it also means "to fart" in slang.