Because today's standard turkey is younger and more tender than in the past, it cooks more quickly. Use these up-to-date USDA recommended times instead of those found in older cookbooks and references. Cook at 325 degrees. A whole turkey is safe when cooked to a minimum internal temperature of 165 degrees as measured with a food thermometer, according to the USDA. Check the internal temperature in the innermost part of the thigh and wing and the thickest part of the breast. If cooking stuffing inside the bird, make sure the center of the stuffing reaches 165 degrees. Even if your turkey has a "pop-up" temperature indicator, the USDA recommends checking the internal temperature with a food thermometer.