Effects of Medications on Heat Loss Capacity in Chronic Disease Patients: Health Implications Amidst Global Warming

agents used to treat or manage diseases can modify the level of heat strain ex-perienced by chronically ill and elderly patients via dif-ferent mechanistic pathways. Human thermoregulation is a crucial homeostatic process that maintains body tem-perature within a narrow range during heat stress through dry (i.e., increasing skin blood flow) and evapo-rative (i.e., sweating) heat loss, as well as active inhibition of thermogenesis, which is crucial to avoid overheating. Medications can independently and synergistically inter-act with aging and chronic disease to alter homeostatic responses to rising body temperature during heat stress. This review focuses on the physiologic changes, with spe-cific emphasis on thermolytic processes, associated with medication use during heat stress. The review begins by providing readers with a background of the global chronic disease burden. Human thermoregulation and aging effects are then summarized to give an understand-ing of the unique physiologic changes faced by older adults. The effects of common chronic diseases on tem-perature regulation are outlined in the main sections. Physiologic impacts of common medications used to treat these diseases are reviewed in detail, with emphasis on the mechanisms by which these medications alter ther-molysis during heat stress. The review concludes by providing perspectives on the need to understand the ef-fects of medication use in hot environments, as well as a summary table of all clinical considerations and research needs of the medications included in this review.Significance Statement--Long-term medications modulate thermoregulatory function, resulting in ex-cess physiological strain and predisposing patients to adverse health outcomes during prolonged exposures to extreme heat during rest and physical work (e.g., exercise). Understanding the medication-specific mech-anisms of altered thermoregulation has importance in both clinical and research settings, paving the way for work toward refining current medication prescription recommendations and formulating mitigation strategies for adverse drug effects in the heat in chronically ill patients.