BACKGROUND: This study aimed to investigate the epidemiological and clinical characteristics of patients with heat-related illness, and guide the prevention, diagnosis and treatment of heat-related illness. METHODS: From June 2013 to August 2013, seventy patients with heat-related illness were treated at Jinshan Hospital of Fudan University, and their epidemiological characteristics, laboratory results, treatment and prognosis were retrospectively analyzed. RESULTS: In the 70 patients, 18 patients suffered from heat stroke and 52 patients from non-heat stroke. When the environmnent temperature was above 35 degrees C, the body temperature of the patients began to increase markedly. The patients with heat stroke were significantly older than those with non-heat stroke (P<0.05). The body temperature, heart rate, blood glucose, blood lactate dehydrogenase and blood creatine kinase in the patients with heat stroke were higher than those in the patients with non-heat stroke (P<0.05). Blood lactate dehydrogenase and blood creatine kinase were positively correlated with body temperature (r=0.801). CONCLUSION: When the environmental temperature goes above 35 degrees C, heat-related illness should be prevented, especially in the elderly. The body temperature, heart rate, blood glucose, blood lactate dehydrogenase and blood creatine kinase in patients with heat stroke are higher than those in patients with non-heat stroke. Blood lactate dehydrogenase and blood creatine kinase are positively correlated with body temperature, but their relationship with heat-related illness awaits further study.