The sun hadn’t yet begun to scorch the sky over Arches National Park when Kendra Hurley and her family set out on the well-worn trail to Delicate Arch. In fact, as far as July temperatures in the park go, it felt fairly balmy. The high had been forecast to be in the low 90s. The week before, Arches hadn’t seen a day below 100.

Maybe that’s why so many people were caught unprepared. Maybe that’s why Hurley saw so much lethargy along the relatively moderate, 3-mile trail.

One boy, around 10 years old, passed out from the heat and hit his head, she said. Then his sister got the chills and had to be tended to by a ranger. Meanwhile, up and down the trail depleted hikers desperately sought shade by huddling under stands of sagebrush. Hurley said it couldn’t have been later than 10 a.m.

“It made me really wonder,” said Hurley, who was visiting from New York City, “whether on every hike there’s tons of people passing out all the time.”

Maybe not tons, but heat has been a major issue at most of Utah’s Mighty 5 national parks, especially in recent years, and climate change isn’t helping. In three of the state’s busiest national parks — Zion, Arches and Canyonlands — park spokespeople say heat-related issues make up the bulk of search and rescue calls. They start coming in May and can stretch into September, as evidenced by this week’s heat wave, which is expected to bring highs of near 100 degrees to many of the parks.

The parks have taken measures to warn people of the risks of recreating in the heat, including messages on their websites and billboard-sized signs at trailheads, but the calls for help keep coming in. So at some point the question must be asked: How hot is too hot to enjoy Utah’s national parks?

The heat is on

At Zion, the answer to “how hot is too hot?” is apparently 105 degrees.

That’s the temperature at which the park begins shutting down auxiliary services, like ranger talks and outdoor programs. Last year, the park hit that number five times during a record-setting July week in which, according to Accuweather, the high was never below 104. That September, a 32-year-old man died from heatstroke while visiting the park. Zion hasn’t had to shut down for heat yet this year, though it has reached 104 four times, all in July.

While 104 is hot by just about any standard, Zion spokesperson Jonathan Shafer said he wouldn’t call it too hot to visit the park.

“I don’t know if there is ‘too hot,’” he said. “But that’s subjective.”

Shafer said visitors need to be honest with themselves about their heat tolerance and their fitness in relation to the activity they have planned. Someone from a colder climate could see temperatures in the 90s and know it’ll be too much for them. Others coming from hot-but-humid locales might scoff at triple-digit heat only to find that it’s a totally different animal when combined with elevation and aridity.

That’s why even Bryce Canyon, which has never seen a day on record in the triple digits and which prides itself on being an escape when the oven is on at the state’s other four national parks, sometimes gets search-and-rescue calls from people struggling with the heat.

“We do see some search and rescue situations that [heat] can be a factor in,” said Bryce Canyon spokesperson Peter Densmore. “Typically the elevation, which does cool things down, kind of has that flip side to it where dehydration can happen a lot more quickly in high elevation. You’re breathing more heavily in the thinner air, also drier air. That can all kind of compound together.”

What may seem like a minor misjudgment can have disastrous repercussions. Darrell Cashin, the search and rescue liaison for the Washington County sheriff’s office, which monitors all calls reported in Zion, can rattle off numerous examples of people who died after reporting heat-related illnesses while on the trails.

“It happens a lot,” Cashin said. “People come into this area, they don’t live here, they don’t understand it. The dry heat just dehydrates them so much. And then they’re also visiting the area, so they’re out hiking and mountain biking and doing all these activities day after day and it takes a toll on them until one day they all go down.”

Hoping to break the pattern, some parks have begun taking a more proactive approach.

Be prepared

The thing that confounded Hurley more than anything during her July trip to Arches was her interactions with an older couple who ran out of water.

When she first met them, they had just left Delicate Arch and begun the hike back down the trail. They carried two, maybe three, “tiny little water bottles.” And they were empty. Hurley, who acknowledges she usually packs too much water, refilled their bottles. Then she refilled them again when she caught up to the couple during her own return.

What was really exasperating, though, was that she saw the couple later in the day on another trail ... and they were out of water again.

“There were huge signs at the beginning [of the trail] saying, like, how much water to bring,” she said. “But I think people see how long the hike is and, you know, it doesn’t really register as this is a real need.”

That kind of attitude and behavior, Arches officials believe, combined with record-setting visitation, caused the park to field the most search and rescue calls in its history last year. In response, Arches hired a preventative search-and-rescue (PSAR) manager whose job it is to coordinate the effort to alert visitors to risks — especially pertaining to heat — before they get into the backcountry or into trouble.

The idea of sending someone, usually a ranger or an intern, out to parking lots and trailheads to intercept potential victims of heatstroke is just starting to catch on in Utah. Neither Zion nor Capitol Reef have formal programs. Instead, they rely on rangers to spread information and offer guidance to visitors when they see them in the park. Bryce Canyon, meanwhile, has had a PSAR program since 2016, Densmore said, with noticeable success. Arches has also employed PSARs for the past five or six years, according to park spokesperson Kait Thomas, but this is the first year the program was formalized.

“We were just seeing this constant increase in the trend and more and more accidents were happening and more and more patients were being overheated or having issues in general,” she said. “So we decided that we needed to really focus on” educating visitors about heat-related illnesses.

The measure appears to be working. Last year, Arches fielded 108 search and rescue calls between January and July. This year, the number was 81 for that same time period, though that could also be influenced by lower visitation.

What more can parks do? Not much, officials say. Not without taking the wild out of the wilderness, which they are understandably reluctant to do. Visitors play in the national parks at their own risk (which is why, for example, Zion’s Angels Landing remains a popular hike despite a spate of deaths there in recent years). And many people know the risks of hiking in the heat before they step onto the trail. They just either think heatstroke won’t happen to them or, as Shafer suggested, they think it’s worth risking it because they don’t know if or when they’ll be back to the park again.

But officials say if those visitors would just make a few tweaks to their plans, like going earlier in the day, hydrating well before as well as during a long hike and bringing a salty snack, it will rarely be too hot — or cold, for that matter — to visit one of Utah’s national parks.

“This is such a land of extremes, right? Temperatures in the summer are over 100 degrees consecutively for days. And then you have well-below-freezing temperatures,” Thomas said.

“I think any time is an absolutely spectacular time, just as long as you know how to prepare.”

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