Beat the Heat
Our bodies have some incredible mechanisms to dissipate heat and regulate temperature. But, as we come into the heat of the summer, it’s more important than ever to ensure we support our body’s natural functions, especially during high-intensity activities.
In early December 2024, I was running a trail race in the hills of Malibu, California. We were hiking on a hot and dusty stretch of singletrack, with the midday sun bearing down at 78 degrees. I had just passed a runner who was stopped and dizzy, but standing. He was definitely overheated, but not in terrible shape. I myself was feeling the heat too, and had slowed my pace to try to bring my heart rate down. Then, at about mile 22, I came up on a runner who was sitting in the middle of the trail, clearly not doing well.
I welcomed the excuse to stop and see what I could do for her. She said she felt nauseous and dizzy, two classic symptoms of heat exhaustion. The very first step was getting her out of the sun, so another runner and I moved her to a tiny, shaded spot. Several runners stopped and offered water, electrolytes, and their concerns. We were all concerned.
But the reality was we were five miles from the next aid station and this runner was unable to walk, had muscle spasms, and was nearly vomiting. I sat with her for a few minutes while others poured water on her head, and we talked about “telling the aid station” fantasizing that a rescue would be like snapping our fingers and—poof!—done. But then it occurred to me that a rescue would take forever. She would have to try to walk. She did not want to be alone, nor was she in any shape to be left, so I soon realized I would be staying with her.
Eventually, she started moving very slowly up the canyon. We took lots of slow steps, a few stops, and another rest in the shade to cool down. At a slow pace, we made it five miles to the next aid station where we were welcomed by relieved staff who had been worried. They’d sent someone with ice and water to meet us as we approached. We enjoyed a Coke, joked around, praised the aid station, and hung out for a bit. By that time of day it was cooler, and she felt that she wanted to try to finish the race. With about four miles left, we slowly jogged to the end, taking whatever brakes felt necessary and ensuring she kept drinking fluids.
I learned a lot that day about the value of recognizing symptoms of heat exhaustion early, in this case nausea and dizziness, and the effectiveness of stopping physical activity and sitting in the shade to cool down. I also learned you can’t rush the recovery of heat exhaustion—it takes time. When we finally did start to move, the runner was really vulnerable to recurring exhaustion and needed to stop in the shade several times throughout our walk.
One way to help protect yourself from heat exhaustion is to spend time training in the heat, while being sure to not push yourself too much. Although this race was during the winter, the region's latitude contributed to warm temps and caught a lot of people from further north off guard. Whether or not you have time to acclimate, there are numerous tactics to help prevent heat exhaustion:
Plan to drink a liter of water per hour of exercise in the heat. This is probably the most important preventative measure in fending off heat exhaustion.
Avoid strenuous exercise throughout the hottest part of the day. If you are hiking, running, biking, try to get most of your miles in during the morning, or plan your route to avoid open and exposed areas in the late afternoon. Shade makes a huge difference and can be up to 10 degrees cooler.
Be sure to replace electrolytes if you are sweating a lot. You lose a lot of salt in your sweat and it can be dangerous if you do not replace it as you drink water.
If you start to feel too hot, dizzy, or nauseous, it is important to get into the shade, sit down, and stop moving to cool yourself down. You can try dripping cold water on your head, down the back of your neck, or sitting by (or in) a creek or other water source.
