Staying cool in hot weather comes down to helping your body do what it already does naturally: move heat from your core to your skin and release it into the environment. Your body sheds heat through four pathways: radiation (emitting warmth from your skin), convection (moving air carrying heat away), conduction (touching something cooler), and evaporation (sweat turning to vapor). Every effective cooling strategy amplifies one or more of these processes. Here’s how to use that to your advantage.
Choose the Right Fabrics
What you wear matters more than most people realize. Linen is one of the best hot-weather fabrics because it absorbs and releases moisture quickly and conducts heat away from your skin, which is why it feels cool to the touch even on a warm day. Lightweight cotton is a solid second choice, especially in loose weaves that allow air to circulate against your skin. Tight-fitting synthetic fabrics designed for “moisture wicking” can work during exercise, but for everyday wear in the heat, a loose linen or cotton shirt will outperform them by allowing more convection across your skin’s surface.
Color matters too. Light colors reflect sunlight, while dark fabrics absorb it and radiate that heat onto your body. Loose fits beat tight fits because the air gap between fabric and skin acts as a ventilation layer, carrying heat away each time you move.
Cool Your Body at the Right Spots
Placing something cold on your skin works through conduction, and some locations are far more effective than others. The palms of your hands contain specialized blood vessel structures called arteriovenous anastomoses that allow large volumes of blood to flow close to the surface. Running cool water over your hands, holding a cold bottle, or even dunking your forearms in cool water can pull heat from your bloodstream surprisingly fast.
Your wrists, the sides of your neck, and the insides of your elbows are other spots where blood vessels sit near the surface. A damp cloth on these areas will cool circulating blood before it returns to your core. Interestingly, research on neck cooling shows it makes you feel cooler without actually lowering your core temperature much, so it’s useful for comfort but shouldn’t be your only strategy if you’re genuinely overheating. An ice vest covering the chest is more effective at reducing whole-body skin temperature because the chest accounts for a disproportionately large share of your overall skin temperature reading.
Take Lukewarm Showers, Not Ice Cold
A blast of cold water feels amazing in the moment, but it triggers vasoconstriction, meaning the blood vessels near your skin tighten up and reduce blood flow to the surface. That’s the opposite of what you want for sustained cooling, since your body needs blood flowing to the skin to release heat. A lukewarm shower cools you without triggering that clamping response, and the thin layer of water left on your skin afterward continues pulling heat away as it evaporates. If you do prefer cold water, keep the exposure brief so the constriction effect doesn’t trap heat in your core.
Ventilate Your Home Strategically
You don’t need air conditioning to meaningfully cool a room. Ceiling fans and whole-building fans can create an effective temperature drop of up to 9°F while using roughly one-tenth the electricity of an air conditioner. The key is thinking about airflow as a circuit: air needs a way in and a way out. Open windows on opposite sides of your home to create cross-ventilation, with the windward side (where the breeze is coming from) supplying air and the leeward side letting it escape. If you only have windows on one side, place a fan facing outward in one window to pull air through the room, while another window serves as the intake.
At night, when outdoor temperatures drop, open windows on multiple floors if possible. Hot air rises, so upper-level windows act as exhaust vents while cooler air enters through lower openings. This “stack effect” can flush a surprising amount of heat out of your home overnight. Close windows and blinds first thing in the morning before the day heats up to trap that cooler air inside.
Eat and Drink for Cooling
Digesting food generates heat. Protein produces slightly more body heat during digestion than carbohydrates or fats because it requires more metabolic work to break down. On extremely hot days, lighter meals with more fruits, vegetables, and carbohydrates will raise your core temperature less than a heavy steak dinner. Eating smaller portions more frequently also reduces the post-meal heat spike that comes with large meals, the same effect that makes you flushed and sweaty after overeating.
Temperature of food matters in a straightforward way: a cold salad adds less thermal energy to your body than a hot bowl of soup. Staying well hydrated is essential because your body can lose over a liter of sweat per hour in extreme heat, and once you’re dehydrated, sweating slows down, removing your primary cooling mechanism. Water is sufficient for most situations. If you’re sweating heavily for extended periods, adding electrolytes helps your body retain that fluid.
Sleep Better in the Heat
Your core body temperature naturally drops as part of falling asleep, and a hot room interferes with that process. The ideal bedroom temperature for quality sleep is between 60 and 67°F (15 to 19°C). Once the room climbs above 70°F, you’re more likely to experience restlessness, wake up more often, and spend less time in REM sleep, the phase most important for mental recovery.
If you can’t get your room that cool, work with what you have. A fan pointed near (not directly at) your bed improves convective cooling. Sleeping on cotton or linen sheets rather than polyester allows moisture to move away from your body. A damp towel draped over a fan creates a makeshift evaporative cooler. Some people freeze a water bottle and place it at the foot of the bed, which cools the sheets through conduction without being uncomfortable against your skin.
Recognize When Heat Becomes Dangerous
Heat-related illness exists on a spectrum, and knowing the warning signs lets you act before things escalate. Heat cramps, the mildest form, involve muscle pain or spasms during heavy sweating. Moving to a cool place and hydrating usually resolves them.
Heat exhaustion is more serious. Symptoms include heavy sweating with cold, pale, clammy skin, a fast but weak pulse, nausea, dizziness, and headache. This is your body signaling that its cooling systems are overwhelmed. Moving to air conditioning, applying cool cloths, and sipping water are critical at this stage.
Heat stroke is a medical emergency. The hallmarks are a core body temperature of 103°F or higher, hot skin that may be red and dry (sweating sometimes stops), a fast and strong pulse, confusion, and possible loss of consciousness. At this point the body’s thermoregulation has failed. Call emergency services immediately and begin cooling the person with whatever is available: cold water, ice packs on the neck, armpits, and groin, or immersion if possible.
Why Humidity Changes Everything
Your body’s most powerful cooling tool is sweat evaporation, and humidity directly undermines it. When the air is already saturated with moisture, sweat sits on your skin instead of evaporating, and you lose that cooling effect almost entirely. Scientists measure this with “wet-bulb temperature,” which accounts for both heat and humidity. A wet-bulb temperature of 35°C (95°F) was long considered the theoretical human survivability limit, but controlled experiments have found that young, healthy adults actually hit their cooling limits at wet-bulb temperatures between 25°C and 31°C (77 to 88°F), depending on whether conditions are dry or humid. That’s much lower than previously assumed.
The practical takeaway: a 95°F day with low humidity is far more manageable than an 85°F day with very high humidity, because in the humid scenario your sweat can’t do its job. On humid days, prioritize air-conditioned spaces, fans that move air across your skin, and reducing physical exertion during peak afternoon hours.