A Paramedic’s Guide to Staying Hydrated in Extreme Heat: Beyond Water and Sports Drinks
Summer heat doesn’t negotiate with EMS schedules. Long shifts, heavy gear, and back‑to‑back calls can drain even the most seasoned providers. After more than 40 years in EMS, I’ve learned that staying hydrated isn’t just about drinking more water—it’s about understanding what the body loses, what it needs replaced, and how quickly heat can sneak up on us.
Three moments from my career have shaped how I think about hydration: a Juneteenth press trip in Houston, a long, sweltering day doing inspections in Memphis nearly 20 years ago, and countless 9‑1‑1 calls during which a simple cooler in the ambulance made all the difference. Together, they’ve taught me that hydration is cultural, practical, and deeply personal—and that EMS providers often underestimate how vulnerable we are to heat.
What Houston Taught Me About Hydration
Two years ago, I was invited to a Juneteenth celebration in Houston during a press trip exploring the history and cultural legacy of the holiday. One evening featured a dinner where the chefs built the entire menu around watermelon—not as a novelty, but as a thoughtful, intentional celebration of heritage. Watermelon cocktails, mains, sides, and desserts filled the table, each one bright, cooling, and deeply hydrating.
That night reframed something I’d known for years in EMS: watermelon is one of the most effective natural hydration tools we overlook. Watermelon is more than 90% water and contains potassium, magnesium, and L‑citrulline, which supports vasodilation and blood flow.1 It’s easy on the stomach during long, hot shifts and provides hydration without the sugar load of commercial drinks.
In Houston, I saw it used not just as food, but as fuel—and it reminded me that hydration can come from more than a bottle.
A Memphis Memory: When Tomato Juice Saved the Day
About 20 years ago, I was working in Memphis during a stretch of brutal summer heat. Our team was doing group inspections for the state, moving from site to site with little shade and even less time to rest. By the time we stopped for dinner around 6 p.m., we were all feeling the effects of dehydration—the kind that creeps up after hours of sweating and not replacing electrolytes.
I almost ordered a Diet Coke out of habit, but something on the menu caught my eye: tomato juice. My body practically shouted for it. I ordered a glass, and it hit the spot immediately—salty, hydrating, and restorative. My colleagues followed my lead, and within minutes, we all felt noticeably better.
Research supports what my body already knew: Tomato juice contains an ideal sodium‑potassium balance for electrolyte replacement and performs as well as sports drinks for post‑exertion recovery.2
A Cooler, a Compartment Door, and a Lesson in Crew Care
When I was running 9‑1‑1 calls full time, I kept a small cooler tucked into the back side compartment of the ambulance. Inside were hand towels layered with chipped ice and a few bottles of cold water. After wrecks, structure fires, or cardiac arrests, I’d swing that compartment door open and hand out iced towels and water to firefighters, rescue techs, and fellow medics.
It was a simple gesture, but it made a difference. People remembered it. Some even told me later that those cold towels kept them from overheating on scenes where they didn’t realize how far they were slipping.
That cooler taught me something important: Hydration is a team effort. We look out for each other, because heat doesn’t care what patch you wear.
The Physiology of Heat: Why EMS Providers Are at Higher Risk
EMS providers face a perfect storm of heat stress factors: heavy PPE that traps heat, high call volume that limits rest, asphalt and concrete radiating heat, stress hormones increasing metabolic heat production, and shift work that disrupts normal hydration cues.
In the field, this risk is magnified by the realities of our work. We routinely respond in full bunker gear or heavy turnout coats that trap body heat like an oven. Prolonged extrications on hot asphalt, patient carries up multiple flights of stairs, and standing in direct sun while managing scenes turn even routine calls into significant heat stressors.
Add the greenhouse effect inside a poorly air-conditioned ambulance—especially when we’re idling on scene for extended periods—and it’s easy to see why dehydration and heat illness can escalate quickly. Many of us also work 24- or 48-hour shifts during which meals are skipped, bathroom breaks are delayed, and the next call always seems to come right when we need a break the most.
According to the CDC and NIOSH, heat stress impairs cognitive performance, reaction time, and decision‑making—all critical for EMS operations.3 Even mild dehydration (1%–2% body weight loss) can reduce physical performance and increase fatigue.4
You don’t have to feel thirsty to be impaired.
Why Water and Sports Drinks Aren’t Enough
Water rehydrates but doesn’t replace electrolytes. Sports drinks replace electrolytes but often deliver more sugar than the body can comfortably handle during heat stress. Neither addresses the fatigue, sodium loss, and muscle cramping that come with long hours in high temperatures.
Hydration isn’t just about volume—it’s about balance. Electrolyte replacement is essential during prolonged heat exposure, especially when sweating heavily, according to the American College of Sports Medicine.
Hydration Timing Matters More Than Hydration Volume
One of the biggest mistakes I see providers make is waiting until they’re thirsty. By the time thirst hits, you’re already behind.
Evidence supports a “slow and steady” approach: small sips throughout the shift, a little extra before you start, and something with electrolytes every few hours. Big chugs of water all at once tend to sit heavy and can worsen nausea in the heat.
Hydration works best like maintaining a pump: steady flow, not sudden surges.
Hydrating Foods That Work in the Field
Crews don’t always have time to sit down for a meal, but they can grab something quick from a cooler. Watermelon, cucumbers, oranges, grapes, and frozen fruit cups all provide water, electrolytes, and a cooling effect without the sugar load of commercial drinks. Coconut water offers natural electrolytes, and tomato juice—as I learned in Memphis—delivers a near‑perfect sodium‑potassium balance when you’re running low.2
These foods are inexpensive, easy to store, and far more effective than relying on water alone.
A Simple Rule: Check Your Urine
One of the most reliable indicators of hydration is something we all see every day: urine color.
If it’s darker than Mellow Yellow or Mountain Dew, you’re not hydrating enough.
It’s a simple, memorable benchmark—and one that can prevent a lot of heat‑related problems before they start.
Recognizing Heat Injury in Providers
We’re trained to spot heat exhaustion in patients, but we often ignore it in ourselves. Early signs include headache, nausea, irritability, muscle cramps, and decreased urine output. If you’re experiencing these symptoms, you’re already in trouble.
Heat doesn’t care how experienced you are. It doesn’t care how tough you think you are. It catches up with everyone eventually.
Hydration Is Cultural, Practical, and Personal
That night in Houston reminded me that hydration isn’t just a medical issue—it’s cultural and communal. Communities across the South have long relied on foods like watermelon to stay cool in the heat. My Memphis memory taught me that sometimes the body knows exactly what it needs, if we’re willing to listen. And that cooler in the ambulance reminded me that hydration is something we owe each other on every scene.
As we head into another hot summer, I hope these insights help crews stay safer, cooler, and more hydrated on the job. The heat isn’t going anywhere—but with the right strategies, neither are we.
References
1. Tarazona-Díaz MP, Alacid F, Carrasco M, et al. (2013). Watermelon juice: Potential functional drink for sore muscle relief in athletes. Journal of Agricultural and Food Chemistry, 61(31), 7522–7528. https://doi.org/10.1021/jf400964rAmerican College of Sports Medicine. (2007). Exercise and fluid replacement. Medicine & Science in Sports & Exercise, 39(2), 377–390. https://doi.org/10.1249/mss.0b013e31802ca597
2. Kwon S, Lee S, Lee S, & Lee J. (2015). Tomato juice intake restores post-exercise electrolytes and plasma volume in healthy adults. Food & Nutrition Research, 59, Article 28206. https://doi.org/10.3402/fnr.v59.28206
3. National Institute for Occupational Safety and Health. (2016). Criteria for a recommended standard: Occupational exposure to heat and hot environments (DHHS (NIOSH) Publication No. 2016-106). U.S. Department of Health and Human Services, Centers for Disease Control and Prevention. https://www.cdc.gov/niosh/docs/2016-106/
4. Centers for Disease Control and Prevention. (2024). Heat stress: Work-related heat stress and illness. https://www.cdc.gov/niosh/topics/heatstress (or the current equivalent: https://www.cdc.gov/niosh/heat-stress/about/index.html)
