However, determining when, exactly, hydration breaks are needed comes down to more than just heat. Hydration breaks, in theory, should be calculated based on Wet Bulb Global Temperature (WBGT), which takes into consideration temperature and humidity. And it’s there when the real need for hydration breaks can be calculated.
“To simplify it, say if it’s sunny and it’s humid and there’s, and it’s hot, you’re going to have a high WBGT, and that’s going to increase risk,” Minson explained.
A combination of both humidity and heat, in fact, can be outwardly dangerous. The body, in effect, starts to shut down.
“We’ve got these conditions where we are going outside of what humans can tolerate for long, playing it at intense levels. When it’s humid, we can’t evaporate, our sweat is dripping off us. If your sweat does not evaporate, you’re not dissipating heat. And then you’re losing all that fluid, plus you’re dehydrating your cells and then you start having problems,” Minson said.
USMNT manager Mauricio Pochettino stressed that, in certain situations, there is no other alternative, though, after playing an early-afternoon game in Seattle.
“I think it was necessary,” he said. “It was really hot and it was good to have the water to help both teams in recovery.”
It’s hard to argue with the science there. FIFPro, the international soccer players’ union, has used similar data to advocate for the usage of cooling breaks in conditions when the WBGT goes north of 28 degrees Celcius.
