Chicago, IL – Many Illinois residents woke up sick on Black Friday after large Thanksgiving meals, and state health officials say food-poisoning risks tied to undercooked turkey and improperly handled leftovers may be contributing to a rise in stomach illness reports.

According to the Illinois Department of Public Health, the day after Thanksgiving frequently brings an increase in nausea, stomach cramps, diarrhea, and fatigue. While overeating rich holiday foods can cause discomfort, experts say improperly cooked poultry and food left out too long are among the most common drivers of post-holiday illness across Illinois.

Large turkeys are especially difficult to cook thoroughly. The thickest areas—deep inside the breast and thigh—often fail to reach the required 165°F internal temperature even when the outer layers appear fully cooked. Many families remove the turkey early to keep it moist, unintentionally increasing exposure to bacteria such as Salmonella and Campylobacter, both commonly linked to undercooked poultry.

Improper leftover handling adds further risk. Illinois’ Thanksgiving buffets, potlucks, and extended family gatherings often leave food sitting out at room temperature for hours. Once dishes remain in the “danger zone” between 40°F and 140°F for more than two hours, bacteria multiply rapidly. Organisms such as Staphylococcus aureus and Bacillus cereus—both associated with food left out too long—can cause sudden vomiting and stomach discomfort.

Nutrition specialists recommend discarding questionable leftovers, reheating all foods to 165°F, and staying hydrated if symptoms develop. Severe vomiting, dehydration, high fever, or symptoms lasting more than 24 hours should be evaluated by a medical professional.

ADDITIONAL SAFETY TIPS

✓ Check leftovers: Discard anything left out for more than 2 hours.
✓ Reheat properly: Heat all leftovers to 165°F before eating.
✓ Watch for symptoms: Sudden nausea, cramps, or diarrhea may indicate bacterial illness.
✓ Cook turkey fully: Verify temperature at the thickest parts of the bird.
✓ Seek care when needed: High fever, dehydration, or blood in stool warrant medical attention.