When outdoor temperatures rise significantly, combined with high humidity, the body’s natural cooling mechanisms can be overwhelmed. The human body maintains a core temperature of about 98.6°F through a delicate process called thermoregulation, with sweating being the primary method of heat dissipation. However, when the air is saturated with moisture, sweat cannot evaporate effectively, preventing the body from shedding heat and causing the internal temperature to rise. This combination of heat and humidity is measured by the “wet-bulb temperature.” When this measure reaches a certain threshold, the inability to cool down quickly leads to serious and preventable heat-related illnesses.
Managing Your Immediate Environment
A proactive approach to severe heat involves keeping indoor areas cool. If using air conditioning, maximize efficiency by ensuring filters are clean and sealing air leaks around windows or doors. If AC is unavailable, maximizing passive cooling techniques can offer significant relief.
One effective passive method is blocking solar radiation by closing blinds or shutters on windows receiving direct sunlight. You can also use temporary window reflectors, such as cardboard covered with aluminum foil, to reflect heat back outside. If the outdoor temperature is cooler than the indoor air (usually at night), open windows and use a fan to draw cooler air in or exhaust warmer air out.
A portable electric fan creates a wind-chill effect that helps sweat evaporate but does not actually cool the air. When the room temperature rises above 90°F, directing a fan onto the body can be counterproductive by blowing hot air over the skin. If a home lacks air conditioning, seek out public cooling centers, libraries, or shopping malls to help the body recover from sustained heat exposure.
Personal Hydration and Activity Adjustments
Maintaining proper hydration is a fundamental defense against heat illness, as sufficient fluid is required for cooling through sweat production. Drink water or other non-alcoholic fluids continuously, even before feeling thirsty, which signals that dehydration has begun. People working or exercising outdoors should consume around eight ounces of water every 20 minutes to keep up with fluid loss.
Avoid beverages that interfere with hydration, such as alcohol, highly caffeinated drinks, and those with excessive sugar, as they contribute to fluid loss. Sports drinks can replace electrolytes like sodium and potassium lost through heavy sweating during prolonged activity. Monitoring urine color—aiming for a pale yellow or straw color—provides a simple check for adequate hydration.
Adjust daily routines to minimize exposure during the hottest parts of the day, typically between 10 a.m. and 7 p.m. Reschedule strenuous activities, like exercise or yard work, for cooler morning or evening hours. When going outside is unavoidable, wear loose-fitting, lightweight, and light-colored clothing to allow air circulation and reflect the sun. Take frequent rest breaks in the shade or a cool place.
Identifying and Responding to Heat Illness
Recognizing the signs of heat illness is important. Heat exhaustion is a milder illness resulting from water and salt loss, characterized by heavy sweating, paleness, muscle cramps, dizziness, nausea, and a rapid, weak pulse. If someone shows these signs, immediately move them to a cool, shaded area and have them lie down.
First-aid includes loosening clothing and applying cool, wet cloths or a sponge bath to lower body temperature. If the person is conscious and not vomiting, give small sips of water or a sports drink. Monitor the individual closely; if symptoms worsen or do not improve within 30 minutes, seek professional medical attention.
Heat stroke is a severe, life-threatening emergency where the body’s thermoregulation fails, causing the core temperature to rise to 103°F or higher. Symptoms include cessation of sweating, hot and red skin, confusion, slurred speech, a strong and rapid pulse, or loss of consciousness. If heat stroke is suspected, call emergency services immediately, as delay can be fatal.
While waiting for help, move the person to the coolest environment possible. Begin active cooling by immersing them in cool water or applying ice packs to the neck, armpits, and groin. Do not give fluids if they are confused, unconscious, or unable to swallow safely. The priority is lowering the body temperature quickly while awaiting medical transport.
Protecting High-Risk Individuals and Dependents
Individuals less efficient at regulating temperature require specific precautions, including older adults, infants, young children, and those with chronic health conditions or taking certain medications. Check in regularly with elderly neighbors or relatives who may lack adequate cooling, offering assistance or encouraging them to visit a cooling center.
Infants and young children must be dressed lightly and monitored for irritability or excessive sleepiness, which signals overheating. Pets, including dogs and cats, also struggle to cool themselves efficiently. Animals with short muzzles, like pugs or bulldogs, are at an elevated risk of heat stroke because they cannot pant effectively.
Never leave a child or a pet inside a parked vehicle, even briefly or with the windows cracked. The temperature inside a car can rise rapidly, becoming fatal quickly. Limit walks for pets to the cooler parts of the day, and protect their paw pads from hot asphalt or concrete surfaces.