Unless you leave the tip laying in the food you're frying for an extended time, the blade shouldn't get terribly hot. Really, what I've heard is that so long as you don't let a blade get hot enough to change color, you shouldn't have any issues. As a rule of thumb when using a sander/grinder, you don't want to let the blade get too hot to touch, but that's because localized heating at the point of contact will be much hotter than the blade as heat is dispersed by conducting into the surrounding steel.