Cooking on the stove: what is "too hot" for a pan?
Flick water on the pan.  If it just sits there, it's not hot enough.   If it combines into balls and skates around on the pan, it's either too hot or just right for a wok or blackening something.  If it sizzles and evaporates within a couple of seconds, it should be good for a normal sautee or sweat.