I like fried eggs dropped into very hot coconut oil so that the white crisps up (seriously, try it). However, I worry sometimes that I might be getting the oil too hot and consequently releasing toxins into my food. I've always assumed that taking an oil beyond its smoking point would result in an obvious tell - visible smoke! But I want to be sure that the situation isn't more subtle than that. Perhaps different oils behave differently when approaching their smoke point? Is it safe to assume that if I don't see smoke, the oil hasn't reached its smoke point and therefore won't have any toxic impact on the food I'm cooking? Also, is there any practical way to measure the temperature of transparent (coconut) oil that is being heated in a fry-pan? Will an IR sensor work, or will it simply pick up the temperature of the pan beneath the oil? 
The definition of smoke point is the moment when oil stops glistening and begins to smoke.  So, if you are not seeing smoke, you are below the smoke point.  IR gets confused by a stainless pan (really, any shiny surface), but could help you when shallow frying in cast iron, or dark surfaced pan. If you are just using a coating of oil, the surface temperature of the pan is probably what you want anyway. In a deep frying situation, I use IR to measure oil temperature...much faster, safer, and cleaner than other approaches. 