Football practice has always been something of an extreme sport in the Coachella Valley, where temperatures can flare far above 100 degrees for weeks on end.

But a change in California law authored by an Inland Empire lawmaker requires extra monitoring of young athletes on the hottest days and sets strict guidelines for how and when they can play in extreme heat. The rules will affect high school athletics throughout the state and expand safety practices that schools in the desert have observed for years, said Estevan Valencia, athletic director at Palm Desert High.

“We’ve been playing sports for over 100 years out here,” he said. “Our coaches and parents and kids have all grown up in this type of environment.”

Coaches shift practice schedules to early morning or after sunset, he said, or they call for frequent water breaks and monitor athletes for signs of heat stress, such as red faces or dizziness.

“We’ve been doing this for a long time; now it’s just mandated and monitored,” he said.

The California Interscholastic Federation developed the rules to meet standards set in the law by Assemblymember Kate Sanchez, a Rancho Santa Margarita Republican whose district includes parts of western Riverside County. Though the law passed last year, the regulations took effect in July, in time for back-to-school sports and the recent heat wave.

For Rafael Perez, cross-country coach at Norte Vista High in Riverside, it means reigning in his students’ normally far-ranging runs.

“On high heat days, we limit them to a smaller space so they can pause and have water breaks, rather than having them two miles out and having them have heat-related problems where they’re too far for any support,” Perez said.

Practice in the desert

As temperatures soared to 114 degrees in the Coachella Valley earlier this month, coaches moved practices to cooler times or indoors and vigilantly watched what is called the wet bulb, a handheld instrument at the heart of the new rules.

“The wet bulb looks like a cell phone on steroids,” Valencia said. “We turn it on, and it gives us a reading of temperature, humidity and wind.”

Junior student Isidro Leanos runs along a bike path outside Norte Vista High School in Riverside on Sept. 19, 2024. Photo by Carlin Stiehl for CalMatters

Caption: First: The shadows of students as they stretch before cross-country practice. Last: Students run along a bike path outside of Norte Vista High School in Riverside on Sept. 19, 2024. Photos by Carlin Stiehl for CalMatters

The device is designed to approximate the effect of heat on human bodies, accounting for air movement, sunlight and evaporative cooling. At high humidity a wet bulb reading will be at or near air temperature, but in dryer conditions its temperature measurement drops, estimating the effect of evaporation. It was invented in the 1950s to protect Army and Marine Corps service members from heat illness, and it has been used in sports since then.

The wet bulb is a more universally accepted measurement for heat stress than standard readings of air temperature or a heat index, said Dave Gustafson, director of educational services for Desert Sands Unified School District, which includes Palm Desert High. “It’s a bit of a change from what we’ve been used to.”

The new rules flow from those readings, with escalating restrictions on sports practice and competition at higher wet bulb temperatures. The heat thresholds vary by geographic zones. Coastal areas are in Zone 1, with restrictions at lower temperatures than schools in Zone 2, which is slightly inland. Hotter and dryer inland areas — with the highest heat thresholds — are in Zone 3.

Every school district in the Inland Empire falls in Zone 3.

Training in the hot zones

At the first heat threshold of 82.2 degrees Fahrenheit for Zone 3, coaches must provide more frequent water breaks. At the next heat level football players must shed parts of their uniforms. As heat rises further they’re forbidden to wear any protective gear. At the final heat level of 92.1 degrees Fahrenheit, outdoor practice is forbidden entirely for that zone.

That gives Zone 3 schools a little more leeway to hold hot weather practices than the other schools. But many days early in the athletic season still exceed the temperature limit, which means teams must reschedule or take practice indoors.

“We have to be very flexible,” Valencia said.

The law also requires all campuses with interscholastic sports to draw up an emergency action plan in case of sudden cardiac arrest, concussion or heat illness.

Sanchez, who played volleyball from elementary through high school, crafted the law after learning about the numbers of sports-related traumas and deaths, said Griffin Bovée, her Capitol director.

He cited a report by the National Center for Catastrophic Sport Injury that found 2,878 catastrophic injuries or illnesses in high school and college sports nationwide from 1982 to 2020. That’s about 75 catastrophic injuries or illnesses a year, including two football deaths each year.

“The impetus for the bill was, unfortunately, many instances of student athletes dying from heat stroke,” Bovée said. “Usually the average is two per year who die while playing, which to the assemblywoman is two too many.”

Preventing athletes’ deaths

The Korey Stringer Institute, established in honor of the Minnesota Vikings lineman who died from heatstroke in 2001, wrote in support of Sanchez’ bill, citing heat illness as the third most common cause of school athletic deaths. The institute is at the University of Connecticut.

By far the greatest number of heat-related deaths of high school athletes occurs in football, but basketball, track and field, and cross-country also had significant mortalities.

That’s why when temperatures rise, Perez limits runners to laps on the track or along the campus perimeter where he can keep an eye on them, and he doubles down on water breaks.

Coaches and players say they try to strike a balance between avoiding dangerous heat and preparing for hot weather games. Without some heat conditioning during practice, they’re at risk of illness at competitions.

“In the past when it was really hot, we would still be outside for heat acclimation,” said cross-country team member Natalene Ocampo,15, a sophomore at Norte Vista High School. “But if it was way too hot outside we would go in the weight room.”

Her teammate Liliana Rubalcalva, also a 15-year-old sophomore who is new to cross-country, said even the limited afternoon practices have been a challenge, after her previous habit of solo night runs.

“Starting to run after school because of the heat, the first time I did it, I wasn’t able to do the entire practice,” she said.

Senior student Andrew Hernandez and Junior student Oscar Abad run along a bike path outside Norte Vista High School in Riverside on Sept. 19, 2024. Photo by Carlin Stiehl for CalMatters

Although athletic programs in the Inland Empire and other scorching parts of the state face slightly higher thresholds for heat restrictions than coastal areas, the rules can still leave them at a disadvantage, coaches said.

“Let’s say we have a couple weeks where it’s extremely hot, and we don’t get to practice during the week but play football on Friday night, versus a school in Orange County that has had a full week of practice,” Valencia said, “if you’re not allowed to condition, that could potentially be an issue whether we could compete safely on Friday night.”

To level the playing field, some coaches in extreme heat zones may ask the California Interscholastic Federation to move a sports season back a couple weeks, to avoid the most intense temperatures of summer and early fall, he said.

In the meantime, coaches are watching the wet bulb and pushing practices earlier in the morning and games later in the evening than usual.

“We all love Friday night football games, but recently we’ve had to see start times a lot later than we’re used to,” Valencia said. “But it’s all in the name of keeping our student athletes safe.”

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