Keeping track of temperature is important, especially when you're doing low-and-slow cooking. Low and slow barbecuing will go even lower and slower if you keep opening the lid to check for doneness. (Which is fine if you want to eat around midnight.) Many gas grills come equipped with a thermometer in the center of the lid, but they only tell you what the temperature is in that exact spot, and don’t account for the temperature anywhere else on the grill—such as down on the grill surface, or at either end of the grill. If you want more exact results that tell you when food is done, use a probe-style thermometer such as the ThermoWorks Chef Alarm [Buy Now], or the iDevices iGrill Remote Grill Thermometer [Buy on Amazon]. With these, you insert a temperature probe into your food and run the wire to a monitor outside the grill, so you can track what’s going on without opening the lid and letting heat out. For direct grilling, where the grill stays open, you can use an instant-read thermometer like the ThermoWorks Mk4 Thermapen [Buy Now]. Grilling goes fast, and you don't want to dry out and overcook food while you're guessing if it's actually done or not.