Heat-Related Illnesses

Risk Factors

• Hot and humid weather conditions can contribute to the development of heat rash, particularly in individuals who engage in vigorous physical activity in these environments 1
• Tight-fitting clothing, non-breathable synthetic fabrics, vigorous physical activity, insufficient rest, poor acclimatization, inadequate hydration, obesity, poor physical fitness, and certain medications can increase the risk of heat rash 2
• Children and adolescents participating in sports are at increased risk of heat-related illnesses, including heat rash, due to their unique physiological characteristics 2, 3
• Individuals with certain medical conditions, such as atopic dermatitis, may be more susceptible to heat rash due to impaired sweating function and compromised skin barrier 2

Prevention Strategies

• Taking regular breaks, maintaining proper hydration, and gradually acclimatizing to hot environments can help prevent heat rash in individuals who engage in physical activity in hot weather, as recommended by the American Academy of Pediatrics 2
• Monitoring for early signs of heat-related illness, wearing loose-fitting and lightweight clothing, and ensuring adequate ventilation can help reduce the risk of heat rash 2
• Staying in climate-controlled environments, avoiding sudden temperature changes, and wearing light-colored and loose-fitting clothing can help manage heat urticaria, as recommended by the American Academy of Allergy, Asthma, and Immunology 4

Special Considerations

• Individuals with heat urticaria, a rare type of physical inducible urticaria, may experience itchy erythema and well-demarcated wheals after heat exposure, with systemic symptoms occurring in approximately 50% of cases 5
• Patients with a history of exercise-induced anaphylaxis should be cautious about heat exposure and consider consulting a healthcare professional for personalized guidance, as recommended by the Journal of Allergy and Clinical Immunology 5
• Antihistamines, such as H1 and H2 antihistamines, may be beneficial for individuals experiencing histamine reactions worsened by heat, according to the American Academy of Allergy, Asthma, and Immunology 5
• Individuals with mastocytosis, small fiber neuropathy, or airway hyperreactivity may be more susceptible to heat-triggered reactions and should take precautions, as recommended by the European Academy of Allergy and Clinical Immunology and the British Society of Anaesthetists 5, 6, 7
• Maintaining cool environments, staying well-hydrated, and avoiding sudden temperature changes can help alleviate histamine reactions, as suggested by the British Society of Anaesthetists and the American Thoracic Society 7, 8
• Exercise in climate-controlled environments, avoiding exercising after eating histamine-rich foods, and discontinuing exercise at the earliest symptoms of histamine reaction can help prevent temperature-related symptoms, as recommended by the American Academy of Allergy, Asthma, and Immunology 5