At first, it was hard for University of North Carolina football player Kendric Burney to swallow.

They handed him a pill containing a battery, thermometer and radio transmitter and told him it would lodge in his intestine, where it would stick around for one to two days to measure his core body heat.

“I’m not going to lie. The thought of putting that in my stomach was just plain weird,” said Burney, a junior cornerback.

But by gulping down the vitamin-sized CorTemp capsule, Burney and 17 other Tar Heel football players began sweating out data that will be used later this season to help determine whether higher body temperatures increase the possibility of concussions. North Carolina’s coaches also plan to use the data to better regulate drills during practice and during games in heat that often reaches the high 90s through the early stretch of fall games.

“That allows us to monitor as coaches, ‘How long do we want to do that particular type of drill?’ ” coach Butch Davis said. “What’s appropriate for a receiver might not be appropriate for an offensive lineman. So I think it’s brilliant.”

The CorTemp pill — a white, silicone-coated capsule big enough “that it feels like you’re swallowing a gummy bear,” according to offensive lineman Alan Pelc — was originally developed by NASA to measure astronauts’ body temperature in space. But over the last six years, scores of football teams have used the $40-per-pop doses to better learn how to beat the heat on the field.

It works like this: Players ingest the pills about five hours before practice; the removal of an attached magnet activates the battery. A device that looks like a remote control, held within six inches of the player, records the temperature via radio transmitter.