Whether we're cooking chicken or burgers, most of us go by sight, smell or taste to figure out when they're ready to eat. But your senses aren't necessarily reliable indicators. In the University of California-Davis study mentioned in the introduction, 40 percent of the subjects didn't cook chicken long enough to kill dangerous bacteria [source: Food Safety News].
The only way to ensure that you're cooking safely is to use a food thermometer to make sure that the meat reaches the necessary internal temperature. The latter can vary from food to food – from 140 degrees F (60 degrees C) for precooked ham to 165 degrees F (74 degrees C) for chicken legs [source: Home Food Safety].
Before using your thermometer, test it with ice water or boiling water to confirm that it gives an accurate reading. When it's time to actually use it, check the temperature of the meat while it's being heated in the skillet or on the grill. Be sure to pick the thickest part of the meat, and don't touch the bone, fat or gristle. And afterward, be sure to wash the thermometer with hot, soapy water [source: Home Food Safety].