The document describes a wireless RF technology system called HOT that monitors firefighters' temperatures. It has RF tags that transmit temperature readings to PDAs from up to 300 yards away. The tags can read multiple temperatures simultaneously and have a battery life of over 1 year. A sensor measures forehead skin temperature which correlates to core temperature. Commanders can access temperature trends and personal data of up to 1,000 firefighters on their PDA and get alerts if temperatures rise. Firefighters, their families, and commanders all benefit from the increased safety monitoring of body heat.