If you’ve been feeling more sluggish, achy, or generally “off” during a heat wave, it’s not just in your head. There are three specific things happening inside your body when temperatures spike that drive up inflammation — and inflammation sits at the root of most disease processes, including aging itself. Here’s what those three factors are, and what actually helps with each one. (based on the insights of Dr. Suneel Dhand)
Key Takeaways
- Hot weather increases inflammation through three main pathways: dehydration, reduced movement, and oxidative stress.
- Fluid needs can rise to 10–15 glasses of water a day in very hot weather, along with adequate electrolytes.
- Reduced movement in the heat can lead to muscle atrophy surprisingly quickly, which is directly linked to inflammation.
- Antioxidant-rich foods like blueberries, broccoli, and bell peppers help counter the oxidative stress that increases in heat.
- People with high blood pressure, kidney disease, or heart failure should manage salt intake with their doctor’s specific guidance.
Reason #1: Dehydration
Even on an ordinary day, most people don’t take in enough fluid, and adequate hydration is essential for basic cellular function — your kidneys especially depend on it. In hot weather, fluid loss through sweat magnifies this problem significantly. A reasonable baseline is several glasses of water daily, but on very hot days that can climb to 10 or even 15 glasses depending on how much you’re sweating.
Electrolytes matter here too — potassium, magnesium, and salt. Since sweating heavily also means losing salt, cutting sodium too aggressively during hot weather isn’t necessarily doing you any favors. That said, if you have high blood pressure, kidney disease, or heart failure, salt intake is something to manage specifically with your doctor rather than by general rule of thumb.
As for what to drink: plain water remains the best option. If large volumes of water feel unappealing, a slice of lemon can help make it more palatable. Tea and coffee have a mild diuretic effect but still contribute positively to overall hydration — water is still the better choice, but they’re not working against you either.
Reason #2: Reduced Movement
When it’s hot, especially without reliable air conditioning, people naturally move less — sitting or lying down feels far more appealing than getting up and walking. But reduced movement can lead to muscle atrophy surprisingly quickly, and that has a direct link to inflammation. Getting outside early, before peak heat sets in, doing light movement indoors with fans running, or simple activities like using dumbbells, all help prevent this from compounding.
Reason #3: Oxidative Stress
Oxidative stress refers to the buildup of free radicals as a byproduct of the body’s ongoing chemical processes, and research shows this process increases in hot weather. Hydration and movement both help counter this, but antioxidant intake matters too — particularly from colorful fruits and vegetables rich in vitamins A, C, and E.
Blueberries stand out in particular; a single serving can contain more antioxidants than five servings of many other fruits or vegetables combined. Broccoli and red, yellow, or green bell peppers are also strong choices. If you’re diabetic or managing blood sugar, be mindful of fruit portions and favor whole fruit over juice, since juice lacks the fiber that helps offset its sugar impact.
Putting It All Together
When temperatures rise, you’re more likely to become dehydrated, move less, and experience more oxidative stress — and all three feed directly into inflammation. Staying on top of water and electrolyte intake, keeping some form of movement in your day even when it’s uncomfortable, and leaning into antioxidant-rich foods like blueberries and colorful vegetables can all help offset these effects.
Source: Dr. Suneel Dhand
Frequently Asked Questions
How much water should I actually drink in hot weather?
A reasonable baseline is several glasses a day, but in very hot weather that can rise to 10 or even 15 glasses depending on how much you’re sweating. Individual needs vary, especially with certain medical conditions.
Should I be cutting back on salt when it’s hot?
Not necessarily — heavy sweating also causes salt loss, so overly restricting sodium in hot weather isn’t automatically beneficial. That said, anyone with high blood pressure, kidney disease, or heart failure should follow their doctor’s specific guidance rather than general advice.
Why do I feel less like exercising when it’s hot?
It’s a natural response — heat makes movement feel less appealing, and many people default to sitting or lying down. The issue is that reduced movement can lead to muscle atrophy fairly quickly, which is directly linked to inflammation, so finding ways to stay active still matters.
What foods help fight the effects of heat on the body?
Colorful fruits and vegetables rich in vitamins A, C, and E are especially helpful, with blueberries standing out as a particularly concentrated source of antioxidants, along with broccoli and bell peppers.
Quick Start Checklist
- ☐ Drink water throughout the day, more on especially hot days
- ☐ Add electrolytes — potassium, magnesium, and salt — especially if sweating heavily
- ☐ Get movement in early, before peak heat, or indoors with fans running
- ☐ Add blueberries, broccoli, and colorful bell peppers to your meals
- ☐ Favor whole fruit over juice if managing blood sugar
- ☐ Check with your doctor on salt/fluid intake if you have high blood pressure, kidney disease, or heart failure
Disclaimer: This article is for general informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. If you have a condition affecting fluid, electrolyte, or sodium intake — such as high blood pressure, kidney disease, or heart failure — consult your doctor for guidance specific to your situation.