This Is HOT -- Health Technology

Hothead Technologies in Atlanta created a football helmet that measures body temperature in athletes as they play and sends that information to coaches. The helmet uses a system called HOT (Heat Observation Technology) that incorporates a thermometer in the padding of the helmet and transmits temperatures to coaches so they can be aware of whether a player is close to getting ill.

--http://www.popsci.com/scitech/article/2009-05/burn-notice