A Heat Index Advisory has been issued for the Miami area, alerting residents to the dangers of high temperatures combined with humidity. The National Weather Service warns that the heat index, which reflects how hot it feels when humidity is factored in, is expected to reach levels that pose a significant health risk, particularly for vulnerable populations such as the elderly, children, and individuals with chronic health conditions. Residents are strongly encouraged to take preventive measures to avoid heat-related illnesses, including heat exhaustion and heat stroke, which occur when the body struggles to regulate its temperature effectively.