Hiking during extreme heat can be deadly. Here's why and how to stay safe

A child collapses and later succumbs to the heat after hiking in scorching temperatures on a Phoenix trail. A couple runs out of water near California's Joshua National Park and are airlifted from a dry creek bed. Three hikers die at the Grand Canyon in less than a month amid extreme heat.

A stifling heat wave in the Western U.S. has turned some of its most alluring nature trails deadly. Here's why hiking in extreme heat can be so dangerous and how to keep yourself safe.

The dangers

Heat records have been crumbling this summer in the U.S., creating dangerous conditions for those exerting themselves outside. The U.S. is warming up at a faster rate than the global average. Already this summer Palm Springs, Calif., set an all-time record high of 124, Reno, Nev., saw a record four days of 105-plus heat while parts of Oregon baked through temperatures of 110.

When the body gets overheated, it struggles to perform basic functions.

"It would be similar with somebody having a really bad stomach flu where your body is basically revolting against you," says Phoenix Fire Capt. Rod McDade. "And what happens is, as the body starts to go into a protection mode, it starts shunting everything in to protect the core."

Heatstroke signs include hot, red, dry or damp skin, a fast strong pulse, headache, dizziness, nausea and confusion. Things can get really dangerous when people ignore them.

"The signs and symptoms are there. Their body is telling them, I can't continue, and yet they continue because they don't believe it's a successful hike until they get to the top of the mountain," says McDade. "And that's when we run into problem."

Be prepared

It really is a dry heat in desert environments, so hydrating before, during and after a hike is essential.

"If your water is half gone, turn around and go back," says Claire Miller, a park supervisor with the city of Phoenix. Dress in light, loose-fitting clothing, says Miller, and you'll also need a hat.

Follow other hiking best practices as well, like bringing a phone, appropriate footwear and a hiking buddy who can check in with you.

"Please have respect for our mountain trails," says McDade, of the Phoenix Fire Department. "As you know, they're deadly and we've already found that out so far this summer."

Also try to time your hike to the coolest part of the day, like first thing in the morning or after the sun sets.

"It's a tough environment out there," says Miller. "And even when you're in good shape ... if you go out at the height of the heat, it's hard for anybody."

Furry friends

If you're hiking with a dog, even more caution is needed. In Phoenix, dogs are banned from trails when temperatures crack the triple-digit mark because they have a harder time shedding heat.

Dr. Sandra Faeh of the American Veterinary Medical Association told Morning Edition's Steve Inskeep that it's best to keep animals inside when it's hot out, and brushing out loose fur can help.

Excessive panting, drooling, restlessness, vomiting, diarrhea and even collapsing are all signs the animal is overheating.

Miller, the Phoenix park supervisor, says she's seen firsthand what can happen when a dog suffers from the heat on a trail.

"I've had to help rescue many dead or dying dogs on trails because they'll just be completely faithful and hike with their owner until the end," she says. "It's a tragic situation."

The rescuers

In Phoenix summers, heat-related rescues are common on popular trails.

"We rescued somebody suffering heat exhaustion on Camelback Mountain (Tuesday). We had one the day before. We had one on North Mountain the day before that," says McDade. "We are seeing folks that are unfortunately enjoying these mountain hikes within the city of Phoenix, when really we question you wanting to even do gardening in your backyard."

It can take upwards of 50 people to execute the rescue of a single person, says McDade. And the rescuers may have to haul heavy equipment up steep mountains to reach people.

In the extreme heat, helicopter rescues aren't even possible, because the aircraft can't get the lift they need to fly.

"We're going to risk a lot to save you," says McDade. "So don't just think about yourself. Think about everybody else involved and how dangerous it is."