To describe heat-related illness and provide approaches for treatment in family practice.The MeSH terms heat-related illness and primary care were searched in PubMed. Clinical trials, practice reviews, and systematic reviews were included in this review. Reference lists were reviewed for additional articles.Extreme heat events are increasing in frequency due to climate change and can directly result in heat exhaustion, heat stroke, or death. Exposure to extreme heat also exacerbates underlying health conditions. Patients may be at increased risk of heat-related illness because of underlying sensitivity to heat, increased exposure to heat, or barriers to resources.Family physicians can help prevent heat-related illness by identifying and counselling patients who are at increased risk and by advocating for interventions that reduce the chance of heat-related illness.