The Extreme Heat Warning affects a wide range of locations across Arizona, including urban areas like Phoenix and Tucson, as well as rural regions such as the Northwest Plateau and Yuma County. Residents and visitors are at risk of heat-related illnesses, particularly those engaging in outdoor activities or without access to air conditioning. Vulnerable populations, such as the elderly, children, and individuals with pre-existing health conditions, are especially susceptible to the dangers posed by the extreme temperatures.