How to tolerate heat better without overheating your system

If you’re sweating through your shirt before 10 a.m., ducking into overcooled shops to escape the heat, or waking up exhausted after another sticky night, you’re not alone. Heat is now the baseline—not the exception—in many parts of the world. And most people are managing it poorly. They blast the air-conditioning. They down iced drinks. They sweat through high-protein meals and skip hydration until it’s too late. In short, they override the very system that’s trying to protect them.

The human body already knows how to regulate heat. It sweats. It cools via evaporation. It balances fluid and energy levels. But modern behavior often disrupts those signals. Instead of adapting, we resist—and then wonder why we feel drained, dizzy, or on the verge of collapse by mid-afternoon. This is a systems issue, not just a temperature one. And like any system, it can be trained, optimized, and protected.

Human beings are endothermic and homeothermic. That means we generate internal heat and work hard to maintain a relatively constant core temperature—around 37°C (98.6°F)—no matter what the environment is doing. Our main cooling mechanism is sweat. When sweat evaporates off the skin, it removes heat from the body.

But sweating isn’t automatic if the system lacks inputs. You need water. You need sodium. You need a clear path for evaporation. And you need the body to feel safe enough to expend energy on regulating temperature. Without these inputs, your internal thermostat begins to fail. You sweat less, dehydrate faster, overheat more easily—and recover more slowly. The system is solid. But like any high-functioning machine, it malfunctions if poorly managed.

Some people tolerate heat better than others. And the differences aren’t just behavioral. They’re biological, demographic, and deeply structural.

Young children and older adults have a weaker sweating response. Their bodies don’t cue thirst as early. Their cardiovascular systems are more vulnerable to fluid loss. And their skin surface-to-body-mass ratio often makes efficient cooling harder. That’s why they’re more prone to heat exhaustion, even in mild conditions.

There’s also a gender gap. On average, women experience more discomfort in the heat than men, and the science backs it up. Women tend to have lower muscle mass and higher body fat, which impairs heat dissipation. They sweat less, meaning they rely more on blood flow to the skin to cool down—which is a slower and more energy-intensive process.

Hormones also play a role. Estrogen and progesterone affect thermoregulation, especially during different phases of the menstrual cycle. Some studies have found that women may experience a higher core body temperature during the luteal phase, which makes heat feel more intense.

But it doesn’t stop at biology. Social factors magnify vulnerability. Women and low-income individuals are more likely to work in caregiving, food service, or domestic roles that lack air-conditioned environments or predictable hydration breaks. In heatwaves, mortality rates are higher among women—especially older women—because their lives are structured around heat exposure and low support. Tolerating heat, then, isn’t just about “toughness.” It’s about support systems—internal and external—that either align with the body’s design or clash with it.

Cooling the air isn’t the same as training the body to manage heat. And over-relying on artificial cooling may actually make you more fragile over time.

Air-conditioning works by rapidly lowering ambient temperature. But when used aggressively—dropping indoor temps to 20°C or lower—it creates a thermal cliff. The moment you step outside into 33°C or 35°C heat, your body has to adjust to a massive temperature difference. That shock increases cardiovascular load, raises blood pressure, and can even trigger fainting in sensitive individuals.

In environments where daily movement in and out of cooled spaces is frequent—shopping malls, offices, public transport hubs—this rapid adjustment takes a toll. Your internal regulation system becomes confused, reacting to a yo-yo pattern of cold-to-hot exposure. You sweat too late, drink too little, and recover too slowly.

Instead of making you more comfortable, chronic overcooling weakens your heat tolerance.

A better approach is to use cooling systems as moderation tools—not complete climate escapes. Keep air-conditioning settings within 6–8°C of outside temperatures. Use fans and cross-ventilation to enhance sweat evaporation. Rely on wet cloths, mist sprays, and shaded rest instead of overengineering an indoor freeze.

The goal isn’t comfort at all costs. It’s functional tolerance that holds up in daily life.

Most people are already mildly dehydrated by the time they feel thirsty. A drop of just 1–2% in total body water can impair cognitive function, reduce aerobic performance, and slow thermoregulation. That’s a narrow margin of error when the sun is pushing 34°C and your shirt is already soaked. Hydration isn’t just about drinking more water. It’s about timing, electrolytes, and consistency.

Start the day with 500ml of water within 30 minutes of waking. This replenishes overnight losses and primes your system for early movement. Throughout the day, sip regularly. Don’t wait for thirst cues—especially during intense sun exposure or physical activity.

If you’re sweating heavily, pure water isn’t enough. You need to replace sodium, potassium, and magnesium—the core minerals lost in sweat. A basic electrolyte mix once a day during hot periods can make a significant difference in your ability to cool effectively and recover faster.

Alcohol and caffeine may also need adjustment. Both contribute to fluid loss and can mask early signs of dehydration. In moderation, they’re fine. But in extreme heat, even your coffee routine needs a rethink. Your ability to sweat depends on your ability to rehydrate. And in heat, rehydration isn’t optional. It’s operational.

Food generates heat. That’s a normal part of digestion, known as the thermic effect of food. But not all foods heat the body equally.

Protein-rich meals—especially those heavy in red meat—have a high thermic load. Fatty and processed foods take longer to break down, raising core body temperature. That’s why a greasy barbecue feels so punishing in the summer. Your digestive system becomes a mini furnace. To support heat tolerance, shift to lighter meals during hot spells. Lean proteins like fish or tofu, high-water-content vegetables like cucumber and tomato, and easy-to-digest starches like rice or noodles reduce internal heat load.

Cool doesn’t have to mean raw. Cooked vegetables and soups—served warm but not scalding—often hydrate better than salads. Soups in hot climates persist not because people like suffering, but because they hydrate while nourishing. Hydrating fruits—watermelon, papaya, citrus—double as fluid delivery and blood sugar regulation. Avoid ultra-sugary snacks or heavy dairy, which slow digestion and reduce thermic efficiency. Your food is either helping you regulate or forcing you to fight your own body. In heat, every bite counts.

The body moves differently in heat. Blood flow shifts toward the skin to facilitate cooling, reducing oxygen availability to muscles. Sweating accelerates, increasing fluid loss. Perceived effort climbs. Fatigue sets in faster. This doesn’t mean you stop moving. But it does mean you move strategically. Early morning—before 8 a.m.—is ideal for intense workouts. The ground is cooler. The air holds less radiant heat. Your body is better able to perform and recover.

Afternoons are not the time to “push through.” If movement is required, reduce intensity, slow pace, and add rest intervals. Walk in the shade. Use water to cool exposed skin. Accept a slower rhythm as functional, not failure.

Evenings can work—but only if the temperature drops. In urban areas with heat-retaining infrastructure, it may remain above 30°C even after sunset. In those cases, bodyweight exercises indoors, light stretching, or balance training may serve better than cardio. Don’t quit movement. Reschedule it. Heat rewards the disciplined, not the reckless.

When heat rises, people assume less clothing equals more comfort. But that’s not always the case. Sweat only cools when it evaporates. Bare skin under direct sun sweats more—but may evaporate less, especially in high humidity or low airflow. Covered skin, when dressed appropriately, often performs better.

Loose-fitting, light-colored clothing made from breathable materials like cotton, bamboo, or linen promotes evaporation while shielding skin from solar radiation. Long sleeves may seem counterintuitive but can keep skin temperature lower than bare arms in direct sun. Synthetic fabrics that trap sweat without wicking or airflow—like polyester blends—can be counterproductive. Even athletic wear may backfire if not designed for tropical heat.

Use hats, sunglasses, and UV sleeves to protect vulnerable areas. Avoid dark colors during outdoor movement. They absorb more heat and can raise skin surface temperature by several degrees. Dress not for exposure, but for thermal performance. Your clothing is your mobile cooling interface. Treat it like gear, not just fashion.

Heat tolerance isn’t fixed. It’s trainable. Spending short, regular periods in warm environments—without relying on extreme cooling—builds the body’s adaptive response. Known as heat acclimatization, this process improves sweat response, lowers resting core temperature, and reduces cardiovascular strain during heat exposure.

Start with 10–15 minutes of walking outdoors during warmer parts of the day. Gradually increase duration over a two-week period. Don’t push into discomfort. Just allow your body to experience, respond, and recover.

Avoid cold showers immediately after heat exposure. Let the body cool down naturally before intervening. This helps reset internal sensors and reinforces adaptive pathways. If you live in a hot climate but spend 90% of your time in air-conditioning, your body remains heat-naïve. The key is exposure—not overload. The system you train is the system that shows up when you need it.

Global temperatures are rising. Between February 2023 and January 2024, the world experienced an average surface air temperature 1.52°C above pre-industrial norms. This is not a heatwave. This is the new climate pattern. Most people are trying to survive heat with gadgets and avoidance. But the truth is simpler—and harder. You have to build your own resilience.

That means learning when to move, what to eat, how to hydrate, and how to cool without overcooling. It means wearing clothing that works with your sweat—not against it. And it means shifting from reactive cooling to proactive adaptation.

Your body already knows how to tolerate heat. You just have to stop breaking its system. No more extreme air-conditioning. No more heavy meals in midday sun. No more waiting until thirst kicks in. The world is getting hotter. You can’t stop that. But you can train your system to stay stable—calm, clear, hydrated, functional. That’s not survival. That’s design.