As summer temperatures climb toward record highs, emergency rooms across the country are filling with heat-related cases. More than 100,000 Americans seek emergency care annually for heat illness, yet many remain unaware of the risks or which communities face the greatest danger.
Heatstroke represents the most severe form of heat illness — a genuine medical emergency that can turn fatal within minutes. Unlike the body's normal cooling mechanisms, heatstroke occurs when those systems fail completely, allowing core temperature to spike to 106 degrees Fahrenheit or higher in as little as 10 to 15 minutes. A person experiencing heatstroke may become confused, dizzy or lose consciousness entirely. Some develop seizures and dangerous heart arrhythmias. This requires immediate emergency care.
Bystanders witnessing someone in heatstroke should call 911 without hesitation. While waiting for paramedics, move the person to shade or air conditioning if available. Apply cold, wet cloths or ice packs to the neck, armpits and groin — areas where major blood vessels run close to the surface. Soak their clothing with cold water. These actions can mean the difference between recovery and death.
Before someone deteriorates into heatstroke, heat exhaustion often signals that the body is in distress. Symptoms include nausea, fatigue, dizziness, headache, profuse sweating and cool, clammy skin. At this stage, intervention can prevent progression to heatstroke. Move immediately to a cool environment, loosen clothing and take a cool bath or apply wet cloths to the body. Drink water. If symptoms worsen — fainting, vomiting — or don't improve within an hour, seek medical attention.
Heat cramps, another heat-related condition, involve painful muscle spasms that occur during or after physical activity in hot weather. Anyone experiencing heat cramps should stop exercising immediately and drink water or an electrolyte solution to replace lost fluids and minerals.
Beyond direct overheating, extreme heat exacerbates existing medical vulnerabilities. High temperatures strain the cardiovascular system, lungs and kidneys. Research shows that interactions between heat and cardiovascular disease account for roughly one in four heat-related deaths. People living with diabetes, chronic respiratory conditions and certain mental health diagnoses face heightened risk when temperatures soar. Medications for managing these conditions can further compromise the body's ability to regulate temperature.
Three populations bear disproportionate vulnerability to extreme heat's effects. The very young and the elderly have reduced physiological capacity to manage temperature fluctuations. Young children cannot always communicate discomfort, while both age groups face heightened dehydration risk. Older adults often take medications that interfere with temperature regulation.
People with chronic medical conditions form the second vulnerable group. Their underlying illnesses already strain organ systems; extreme heat adds pressure that can trigger crises.
The third group includes those with occupational exposure to heat and those experiencing housing insecurity. Outdoor workers, including agricultural laborers, construction crews and delivery drivers, face mandatory heat exposure as a condition of employment. Many lack adequate breaks, shade or access to cold water. People experiencing homelessness have no refuge from heat. Without air conditioning or safe shelter, they depend entirely on whether local cooling centers exist and whether they can access them.
For elderly and very young people, limiting outdoor time during peak heat hours makes sense — exercise in early morning or evening instead. Stay hydrated. Caregivers should monitor time spent outside and watch for warning signs. Never leave children or pets in parked cars; interior temperatures become lethal in minutes.
For people with chronic conditions, similar strategies apply: limit daytime exposure, stay hydrated, take medications as prescribed and seek cool spaces when possible. Consult healthcare providers about how heat affects specific medications.
For outdoor workers, employers must provide mandatory shade, frequent water breaks and time to cool off in air-conditioned spaces. These are basic occupational safety requirements.
For people experiencing homelessness, communities must ensure cooling centers are accessible, free and equipped to serve those without identification or resources. Temporary shelter during heat waves should be guaranteed.
Addressing heat illness also requires confronting the urban heat island effect — the phenomenon where cities, especially low-income neighborhoods with less tree canopy and more pavement, retain dangerous heat. Wealthy neighborhoods often have more parks, trees and green space; poorer neighborhoods become concrete ovens.
Meaningful prevention means planting trees in neighborhoods that have been denied them, requiring developers to incorporate green space and cool roofs in new construction, and ensuring that air conditioning access becomes universal rather than a privilege of the wealthy.
Extreme heat is intensifying as climate change accelerates. Heat waves will become longer, more frequent and more dangerous. Unless structural inequities that leave some people more exposed and less protected are addressed, heat illness will continue to strike hardest at those already bearing the heaviest burdens.
