Undercooked describes food that has not been heated enough — still raw, cold, or hard in parts that should be cooked through. The concern is food safety: pathogens such as Salmonella in poultry, E. coli in minced beef, and Trichinella in pork are destroyed only when the whole portion reaches a sufficient temperature for sufficient time. An undercooked burger that is browned outside but pink and cool in the middle is the classic hazard. Vulnerable groups — pregnant women, young children, the elderly, and the immunocompromised — face the greatest risk and are advised to eat meat and eggs thoroughly cooked. When in doubt, cook it more and check with a thermometer.