Public health officials and emergency physicians warned Americans on Saturday to take precautions against extreme heat, foodborne illness and burns as millions gathered for July 4 celebrations across the United States. The National Weather Service issued heat advisories for several southern and midwestern states.

Rutgers University experts cautioned that people with chronic conditions such as heart disease, diabetes and kidney illness face elevated risks during prolonged high temperatures. They advised staying hydrated, limiting alcohol and avoiding strenuous outdoor activity during peak afternoon hours.

The Centers for Disease Control and Prevention has previously reported that emergency room visits rise on Independence Day, driven by grilling burns, food poisoning and fireworks injuries. The American Burn Association urged caution around barbecues and open flames, noting that thousands of Americans are treated for holiday fireworks injuries each year.

Hospitals in cities including Phoenix, Dallas and Atlanta reported preparing additional emergency capacity for the holiday weekend. Physicians recommended cooking meats thoroughly and refrigerating perishable foods promptly to prevent salmonella and E. coli infections common at summer gatherings.

Dr. Aline Holmes of Rutgers said older adults and young children required particular attention during the heat wave, advising families to check on vulnerable relatives and recognize the early signs of heat exhaustion.