Extreme heat is already driving more illness, and the body needs help staying cool
Summer heat has become more than an inconvenience. With the last 13 months described as the hottest on record, clinicians are seeing more heat-related illness, and the season is starting earlier than many people expect. The physiological problem is straightforward: when air temperature, humidity, and physical exertion all rise together, the body can no longer shed heat efficiently enough to maintain a safe core temperature. Sweating becomes less effective in humid weather because evaporation slows, and without evaporation, the body loses one of its main cooling systems.
Dr. Tess Wiskel, a climate change and human health fellow at the Center for Climate, Health, and the Global Environment and an emergency physician at Beth Israel Deaconess Medical Center, urges people to prepare before overheating begins. The practical goal is not just comfort. It is prevention of heat exhaustion, a condition that can escalate quickly when fluid loss, ambient heat, and prolonged exertion are allowed to stack up.
Hourly planning, hydration, and indoor refuge form the core defense
The most basic protection starts with paying attention to the weather in a more granular way. Hourly forecasts matter more than a daily high and low, because the hottest part of the day can coincide with errands, commuting, yard work, or exercise. Planning around those peaks reduces exposure before the body is stressed.
Hydration is central because sweat is the body’s primary cooling mechanism. As moisture on the skin evaporates, heat leaves with it, but that only works if the fluid losses are being replaced. The article cites National Academy of Medicine guidance of about 11 cups, or 88 ounces, daily for women and 15 cups, or 120 ounces, for men, with the reminder that people who are outdoors or sweating heavily need more. Water-rich foods can contribute meaningfully, especially when appetite drops in the heat.
Air conditioning remains the most reliable environmental control. Indoor cooling is not a luxury during extreme temperatures; it is a direct countermeasure to heat stress. Shopping malls, libraries, movie theaters, and community cooling centers can serve as safe shelter when home cooling is unavailable. In a heat wave, access to conditioned air can determine whether a person stays functional or begins sliding toward dehydration, dizziness, and collapse.
Fans help only when the surrounding air does not overwhelm the body
Fans can move heat away from skin when the surrounding air is cooler than the body or at least not excessively hot. They become less effective when the ambient air itself is scorching. In that setting, the fan should be paired with moisture on the skin. Wetting the skin with a spray bottle or wet wipe gives the fan something to evaporate, restoring evaporative heat loss and improving the body’s ability to offload heat.
Pacing activity is equally important. Physical labor generates internal heat on top of external heat, which is why outdoor work in summer can become dangerous so quickly. Short bouts of exertion followed by rest give circulation and sweating a chance to catch up. This is especially relevant for people who may feel healthy enough to push through but are already losing physiologic reserve in high humidity.
Bring cooling supplies with you whenever you leave home. Water, a handheld fan, wet wipes, and ice packs are simple tools, but they can prevent a long, hot outing from becoming a medical event. Loose clothing also matters because airflow across the skin improves evaporation. Tight, heavy fabrics trap heat and can make sweating less productive.
Clothing and improvised cooling can lower skin temperature fast
High-tech cooling garments are increasingly available, and they work through different mechanisms. Some are designed with fabrics that are activated by water and hold moisture long enough to keep pulling heat away from the body. Others use materials or gels intended to stay cool longer than ordinary cloth. Their value is practical rather than cosmetic: they create a buffer between the skin and the environment, especially when shade and air conditioning are out of reach.
A simple do-it-yourself cooling garment can work too. A kitchen towel or cotton T-shirt soaked in cold water and worn on the head, neck, or torso can help until it dries, then be rewetted. Cold drinks, ice chips, or a popsicle may also lower body temperature while helping with fluid replacement, though gulping too quickly can provoke gastrointestinal discomfort.
Water immersion remains one of the most effective tools when heat stress is building. A cool shower or bath is reasonable, even if the water is not ice-cold. Dr. Wiskel advises water that is cooler than body temperature, followed by a fan afterward to encourage evaporation. For people who cannot bathe, the US Army method of submerging the hands, forearms, and elbows in ice water for five minutes can move cooled blood back toward the core. Ice packs placed near large blood vessels in the elbows, underarms, neck, or inner thighs can serve a similar purpose.
One sentence matters here: if the body is not cooling down after multiple measures, the problem has moved beyond self-care.
Heat exhaustion signs should trigger a low threshold for medical help
Call a doctor’s office or 911 when heat illness is accompanied by excessive sweating, headache, faintness or dizziness, cold clammy skin, a fast or weak pulse, extreme fatigue, or muscle cramps. These are not trivial symptoms. They reflect a body under strain, struggling to maintain circulation, blood pressure, and temperature control at the same time.
Risk is not evenly distributed. Older adults, babies and children, pregnant people, workers outdoors, people taking medications that impair sweating, and those with health conditions including cardiovascular disease deserve special attention. The cardiovascular system is especially vulnerable because it must both support circulation and help redistribute heat toward the skin, a balancing act that can fail when fluid depletion and vascular strain progress together. People who are not in a high-risk group should still check on others, because heat illness often escalates before the affected person fully recognizes the danger.
Extreme heat is not just uncomfortable weather. It is a physiologic stressor that can overwhelm hydration, circulation, and temperature regulation in a matter of hours, and in some cases much sooner.