# What Does Hot Weather Do to the Body?
Summer heat strains your body in multiple ways, triggering a cascade of physiological responses that range from minor discomfort to life-threatening conditions.
When external temperatures rise, your body works to maintain its core temperature around 98.6 degrees Fahrenheit. Blood vessels near your skin dilate to increase heat loss, and you sweat to cool down through evaporation. This process demands extra water and electrolytes. Dehydration follows quickly in hot weather, reducing blood volume and making your heart work harder to circulate oxygen.
Heat exhaustion develops when your body can't cool itself fast enough. Symptoms include heavy sweating, weakness, dizziness, nausea, and headaches. Your core temperature stays below 104 degrees Fahrenheit, but your system is failing. Heat stroke, the more dangerous condition, occurs when core temperature exceeds 104 degrees and sweating stops. Your organs begin to shut down. Heat stroke requires emergency medical attention.
Vulnerable populations face steeper risks. Older adults have reduced sweating ability and slower temperature regulation. Young children can't regulate their temperature efficiently. People taking certain medications, including diuretics and antipsychotics, struggle to cool down. Those with chronic conditions like heart disease, diabetes, or obesity experience amplified strain. Outdoor workers and athletes push their bodies in conditions their cooling systems can't handle.
Even mild heat exposure creates problems over time. Heat reduces mental performance, slows reaction time, and worsens mood. Chronic heat stress contributes to kidney damage from repeated dehydration cycles.
Prevention starts with hydration. Drink water before thirst kicks in, since thirst lags behind actual fluid loss. Limit caffeine and alcohol, which increase dehydration. Wear loose, light-colored clothing. Spend peak heat hours, typically