This document provides an overview of environmental emergencies related to heat and cold exposure. It discusses the body's temperature regulation mechanisms and how hypothermia and hyperthermia can result when heat loss or gain exceeds the body's ability to compensate. Specific types of hypothermia are described, including generalized hypothermia, immersion hypothermia, urban hypothermia, and myxedema coma. Local cold injuries and factors that predispose individuals are also outlined. Treatment priorities for patients with suspected environmental exposures are mentioned.