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.

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Oh, I see now that you're asking how hot should the pan be before even adding oil.

Two things to keep in mind...

1. You want the pan just hot enough to be certain that all moisture is gone from the surface of the pan. Otherwise, the oil could splatter suddenly as it gets hotter and the moisture on the pan vaporizes.

2. If the pan is already hot, the added oil will almost instantly heat up to the same temperature, and you can start the rest of the cooking immediately. If you had added the oil when the pan was cold you would have to wait for the pan to reach temperature-- and might get distracted and then forget about the pan with the oil in it! :-O

Whether or not the pan is "too hot" depends largely on the type of oil (shortening) that you're using and to a lesser extent on what you are cooking. If you just wait long enough that a small sprinkle of water boils away on contact, you'll be OK. If you wait longer, you risk exceeding the smoke point of your shortening.

Every type of oil has a different smoke point. This is the temperature at which the oil smokes (not surprising!). What that means is that the oil is starting to chemically break down and if you attempt to cook with the oil in that state, your food will have an unpleasant bitter burnt taste. The oil will also become sticky and make it hard to manipulate the food while it cooks in the pan. Wikipedia on smoke point.

Extra virgin olive oil (EVOO), for instance, has a lower smoke point than, say, seasame oil. You would never use EVOO to deep-fry fish or stir-fry in super hot wok.

The usual advice is to heat the oil in the pan until you just see the first faint wisp of smoke. You then add the stuff you are cooking in the pan (and this drops the temperature to below the smoke point).

The other thing to consider is what temperatures are too hot for what foods. That varies wildly. The only thing I can generalize is that thick items should not be cooked at a very high temperature unless you are caramelizing or searing the exterior and then finishing the cooking in the oven or crock-pot

In a short answer, if the pan smokes, it's too hot... What'd I'd play with is getting a batch of throw-away (something), for instance biscuits or something with the intent to test your stovetop. Heat the pan to different temps and see what happens to your throw-away food when you put it on the pan.

In short though, smoking is bad. And if it's teflon, it's doubly bad as teflon is only rated for stovetop temps. If a teflon pan gets too hot, the teflon becomes dangerous.

Also, in the context of your answer, "Too hot" is relative to the specific food you're trying to cook... Usually you can drop a few drops of water in an empty pan and watch how fast the drops "skid" away. You'll want it to skid away at different speeds based on what you're cooking.

Editing to put some reference to the teflon comment

From: http://www.truefalse.co.nz/articles/truefalse39-teflonpoisonous.html

These things also make it good to coat a frying pan with. It’s very inert, so it won’t do anything to the food or, more importantly, our insides. It is durable at high temperatures where other plastics would melt or burn. And of course it is extremely slippery.

If you swallow bits of Teflon they won’t hurt you. It’s just plastic. If you burn Teflon, though, things are different. When Teflon is heated too strongly the resulting fumes, for reasons not yet fully understood, are very bad for you. Fortunately it’s hard to get Teflon too hot, but it could possibly happen if a coated pan is left dry on a hot element or in a very hot oven. So don’t do that.

Nothing sticks to Teflon, except the unfounded rumour of its toxicity. But, like the burnt cheese in a frying pan commercial, even that just wipes right off.