KEARNEY, Neb. — As the Kearney Catholic football team prepares to practice, all eyes are on a small, orange device perched atop a tripod.

With a record-setting heat wave suffocating Nebraska, high school sports coaches and administrators take their cues from the wet bulb globe thermometer.

It’s another guideline for coaches like Rashawn Harvey to use to keep student-athletes safe.

“You tell them to stay hydrated, you try to get them in safe situations, try to get your practice time so it’s more conducive and you can get some work done," Harvey said. "The worst thing you want is someone to have a medical emergency out here. Number one is the safety of the kids.”

The wet bulb globe temperature takes into account ambient temperature, humidity, sun angle, wind speed and cloud cover. Mike Moritz is the Warning Coordination Meteorologist for the National Weather Service in Hastings. He says it’s an upgrade over other measurements like the heat index.

“Though it does give us a good reference frame, it’s not always the best index compared to wet bulb globe temperature, which takes in the sunshine and the wind as well and applies it to an activity," Moritz said.

The wet bulb reading corresponds to a color zone on a chart developed by the Korey Stringer Institute at the University of Connecticut. Orange limits practice time to two hours, the red zone cuts it to one hour and black eliminates activities. 

The Nebraska School Activities Association adopted the guidelines last year. Assistant Director Ron Higdon says it’s a more exact system.

“You can have it and it’s site specific. Your turf might have a different reading than 200 yards away in the grass,” Higdon said. “It’s a little more black and white than just guessing on the heat index chart.”

The National Federation of High Schools Foundation supplied some thermometers to each state association and the NSAA bought the remainder needed to give one to each school.

“I think it’s a high priority for our schools, as well," Higdon said. "We just help them with the resources to make sure they’re doing the right things.”

For Harvey and his team, the heat wave and the almighty thermometer are just another variable to adjust to.

“We can’t control the weather right now, but we can control how we respond," Harvey said. "So we can’t practice at our regular, we moved practice back. We gotta be disciplined and understand that we don’t control it, but our desired outcome is to get some practice time in. So we sacrifice a little bit to get that desired outcome that we want.”