The U. S. Department of Agriculture (USDA) Food Safety Inspection Service (FSIS) recommends an internal cooked temperature of 165 to 180 degrees for poultry. The food thermometer depicted here is thermistor-style food thermometer, which uses a resistor (a ceramic semiconductor bonded in the tip with temperature-sensitive epoxy) to measure temperature. The thickness of the probe is approximately 1/8 of an inch and takes roughly 10 seconds to register the temperature on the digital display. Since the semiconductor is in the tip, thermistors can measure temperature in thin foods, as well as thick foods. Because the center of a food is usually cooler than the outer surface, place the tip in the center of the thickest part of the food. This type of thermometer does not remain in the food while it is cooking but should be used near the end of the cooking process. USDA Photo.