Wind chill poses significant risks during cold weather, including frostbite and hypothermia. For instance, at 0°F (-17.8°C) with a 15 mph wind, exposed skin can develop frostbite in approximately 30 minutes. Similarly, during hot weather, high humidity can elevate the heat index, increasing the risk of heat exhaustion and heatstroke. For example, an air temperature of 90°F (32.2°C) with 70% humidity can feel like 106°F (41.1°C). These conditions demand careful planning and precautions to avoid health hazards, particularly for outdoor workers, athletes, and vulnerable populations.