So, besides using them to check for engine cooling system problems or to see if your steaks on the grille are at the right temperature, these guns make a great tool for finding loose or not so obviously corroded electrical connections. The way I do this is to scan the cable in question using the red laser light on the gun. This way I can establish a median temperature in the cable in question. With the engine cranking in this example, I close in on the connection with the laser light. If I see a temperature rise of 25 degrees F or more, I am immediately suspicious of the quality of the connection. This is a simple technique that can help you find some elusive problems, and save you from burning your finger tips!