There's a pill to measure your core body temperature to make sure you and your coaches know when you are overheating.

A small plaque lies before a tree planted in Korey Stringer's memory at Minnesota Vikings training camp. "In Memory of Big K," it reads, honoring the beloved right tackle who died four years ago from heatstroke. There was no way for trainers to monitor players' core temperatures on that sweltering July day when Stringer collapsed, no definitive way to tell that his massive body was overheating beyond its threshold.

But now there is, in the form of a swallowed capsule that measures core body temperature as it passes through the digestive system, and the Vikings -- along with a few other NFL teams -- are using it.

Cool.