I’m an Editor at Outside. Here’s How I Hike Safely in Extreme Heat.

In early June, during a severe heat warning, two of my best friends and I hiked into the Grand Canyon on our way to Havasupai Falls. We had secured our hiking permits six months prior, and didn’t want to lose out on the girl trip of a lifetime even with the intense weather conditions.

But ahead of the launch date on our hiking permit, the canyon was heating up. On June 3, a teenager died from heat-related illness while hiking on Bright Angel Trail along the South Rim. Just a week before we set out on our backpacking trek, three people died from suspected heat illness.

The out-and-back trail from the canyon rim to our campground was about 12 miles, but has an elevation gain of about 2,000 feet in the first two miles. Between additional side hikes and side quests, we clocked around 43 miles total over four days. Because of the desert heat, loose sand, and steep climb out, trails here are considered difficult and strenuous.

To keep our group safe, we had to rethink our backpacking strategy. Here is the protocol we followed to survive a 40-mile trek in triple-digit temps.

Hydrate Before Your Adventure

Preloading hydration and managing electrolytes are a trail-goer’s best friend. Before heading out on the trail, drink water. According to the American Hiking Association, your body feels thirsty when water levels are already low. This means you shouldn’t wait to feel thirsty. Instead, begin drinking water and hydrating ahead of time.

Start Hikes Early or Late

Time your hike to avoid the hottest parts of the day, which the National Park Service says typically fall between 10 A.M. and 4 P.M in the desert. As long as it’s safe to do so and you’re comfortable with the terrain, this may look like starting in the wee hours of the morning or late evening. During our hike into Havasupai, for example, we descended from the trailhead at 6 P.M., arriving at camp around 11:30 P.M. On our hike out, we left camp at 4 in the morning.

Dress Appropriately

When hiking in the desert, exposed skin invites sunburn and dehydration. Sun hoodies are an Outside staff favorite for keeping the sun off your neck and ears. During our backpacking trip, I wore the North Face Light Range sun hoodie every day.

Also consider wide-brimmed hats, bandanas, and other lightweight, loose-fitting, light-colored clothing with a UPF rating to protect your skin from UV rays. Polyester or nylon blend synthetic fabrics wick sweat and dry rapidly to prevent chafing.

Kafka Kool Tie

By far, our favorite cooling hack was the Kafka Kool Tie. Unlike other bandanas that can quickly dry out under the desert sun, the Kafka Kool Tie contains non-toxic polymer crystals that absorb water and retain it for hours. As water evaporates, the company says that the neck ties cool the carotid arteries in the neck, lowering your overall body temperature. Plus, they’re super cute.

Always Carry Enough Water

A standard rule of thumb is to bring between 0.5 and 1 liter of water per hour of hiking in extreme heat, but that can vary depending on conditions such as elevation, activity level, and temperature. Be sure to check in with local guiding companies or other experts for more information.

For more strenuous hikes, consider bringing electrolyte packets or other hydrating tablets.

I love carrying water in a bladder, like this Platypus water bladder. It doesn’t leak, is hardy, and the straw makes it incredibly easy to access during my hikes. I also carried two types of filters: the Sawyer Squeeze Filter (for filling up at camp) and the MSR TrailShot Pocket-Sized Filter for pumping on the trail.

Bring a Sun Tarp

Shade can make a massive difference in protecting yourself from the heat. The air temperature will remain the same whether you’re in direct sunlight or not, but direct sunlight can make it feel up to 15 degrees Fahrenheit warmer, according to the National Weather Service. Direct sunlight may also aggravate common medical conditions, like migraines, autoimmune disorders and respiratory illness, writes the Los Angeles-based healthcare system Cedars-Sinai.

If natural shade from trees or mountains isn’t available, a sun tarp can provide that extra protection. I used the Eno ProFly Sil Rain Tarp for our trip to add extra shade at camp. At 18 ounces, it’s lightweight and doubles as both a bad-weather layer and a desert-sun protector.

Get Out of the Sun When Needed

If at any point you get overheated, get out of the sun and cool down. Heat stroke can strike within 15 minutes, according to the Centers for Disease Control and Prevention. causing the body’s cooling system to essentially fail and lose the ability to regulate temperature. At any point you begin to feel flushed, confused, dizzy, or disoriented, that’s a sign to slow down and cool off. Get out of the sun and begin cooling off by applying cold, wet clothes or clothing to the neck, armpits, and groin.

Call help immediately if you believe you or someone in your group is suffering from heat stroke.