Beat the Florida Heat: What Runners (and Everyone Else) Get Wrong About Hydration

Florida Heat Isn't Like Other Heat

Dr. Greg gets this question a lot, especially from patients who've moved to Jacksonville from other parts of the country: why does Florida heat feel so much worse than other hot climates? The answer comes down to humidity. Dry heat states like Arizona or Nevada let sweat evaporate efficiently, which is exactly what's supposed to cool the body. In Florida's humidity, that evaporation slows down. Sweat sits on the skin instead of doing its job, core temperature climbs faster, and the heart has to work harder to compensate — all while you're already asking it to handle whatever cardiovascular activity brought you outside in the first place.

In Episode 43 of the Movement Driven Podcast, Dr. Greg breaks down why this matters for runners specifically, what most people get wrong about hydration, and how to adjust training as Florida moves deeper into summer.

"Thirsty" Already Means You're Behind

One of the most common mistakes Dr. Greg sees isn't dramatic dehydration — it's the quieter, more common version: just not being hydrated enough. Most people aren't tracking this until they feel thirsty, and by that point, they're already in a deficit. Combine that with running during the hottest parts of the day — Dr. Greg specifically calls out the midday lunch-hour crowd — and the risk compounds quickly.

The fix isn't complicated, but it does require intention: train earlier in the day when possible, respect rising temperatures rather than pushing through them, and treat hydration as something to stay ahead of rather than react to.

Water Alone Isn't the Whole Answer

A theme Dr. Greg returns to often: too much plain water without anything else can actually throw off your electrolyte balance. Long-distance athletes need more than water — sodium, potassium, and magnesium all play a role in how the body holds onto fluid and functions under heat stress. Most of the runners Dr. Greg works with already carry electrolyte chews or supplements alongside their water intake, and he recommends finding a brand and format that works for your own digestive system rather than assuming any one product is universal.

The bigger point: water and electrolytes aren't an either-or. They work together, and skipping one undercuts the other.

Training Has to Adjust With the Season

This year, Northeast Florida didn't get a gradual ramp into summer heat — it went from mild to intense almost overnight. Dr. Greg's guidance here ties back to a principle he repeats often in the clinic: increasing volume or intensity too quickly is one of the most common paths to injury, and that applies to heat exposure just as much as mileage. When the temperature jumps faster than the body can adapt, runners need to adjust mileage, frequency, and time of day accordingly — not push through on the same schedule that worked in cooler months.

It's Not Just About Athletes

With the Fourth of July approaching, Dr. Greg points out that hydration risk isn't limited to runners and structured athletes. A full day outdoors — biking, beach time, alcohol — creates the same physical strain, just without anyone thinking of it as "training." Dr. Greg references a local ER physician colleague who covers outdoor events like Jaguars games: the busiest days are almost always the hottest ones, and the cases are almost always the same — too much alcohol, not enough water, and heat exhaustion that could have been avoided with basic hydration habits.

The takeaway: if you're outside for hours in Florida heat, you're in the same risk category as a runner, whether or not you think of yourself as exercising.

The Simple Habit That Makes the Difference

Heat isn't the enemy — it's something to respect and plan around. Whether you're training for a race, getting back into running for the first time, or just spending the Fourth of July at the beach, the same principles apply: hydrate ahead of thirst, pair water with electrolytes, train earlier when you can, and adjust as the season heats up.

Book a free 15-minute discovery call or schedule your first evaluation for $79. Dr. Greg sees patients at both the Jacksonville and St. Johns locations.

🎧 Listen to the full episode on Spotify, Apple Podcasts, or YouTube.