Feeling a little dizzy or unusually tired on a hot day can seem harmless right up until your body can no longer compensate.
Singer Ray LaMontagne recently collapsed during a performance in Nashville, where temperatures outside had reached triple digits. His management later said he was being treated for heat-related dehydration.
It’s an extreme example of something that can happen far more quietly to people gardening, exercising, traveling, attending outdoor events or simply spending too much time in the heat. Thirst isn’t always the first—or best—warning that you’re getting into trouble.
Heat makes your body work harder
Your body needs to maintain a relatively narrow internal temperature range. When you’re hot, blood flow to the skin increases and sweating helps release heat through evaporation. But sweating also removes fluid. If you don’t replace enough of it, blood volume can decrease and your cardiovascular system has to work harder.
High humidity complicates matters because sweat doesn’t evaporate as efficiently, reducing one of the body’s most important cooling mechanisms.
The early symptoms can seem ordinary
According to the CDC, signs that your body is overheating can include heavy sweating, dizziness, headache, weakness, nausea, shortness of breath and muscle cramps. Those symptoms are easy to rationalize. Maybe you didn’t sleep well. Maybe you’re hungry. Maybe you’re just tired.
That’s precisely why paying attention to the circumstances matters. If you’re in significant heat and suddenly feel weak, dizzy or nauseated, don’t assume you can simply push through it.
Heat exhaustion and heat stroke aren’t the same
Heat-related illness exists on a spectrum. Heat exhaustion can involve heavy sweating, weakness, dizziness, nausea and headache. Heat stroke is much more dangerous. It occurs when the body loses its ability to control its temperature.
The CDC’s occupational heat guidance warns that during heat stroke, body temperature can rise rapidly and the condition can cause permanent disability or death without emergency treatment. Confusion, altered behavior, fainting or loss of consciousness in the heat should therefore never be dismissed as ordinary dehydration.
You don’t have to be exercising outdoors
Heat illness isn’t limited to marathon runners and construction workers. Older adults can be especially vulnerable because thirst perception and temperature regulation can change with age. Certain medications and chronic medical conditions can also affect the body’s response to heat. Indoor environments can become dangerous, too.
An apartment, workplace, performance space or house without adequate cooling can expose someone to significant heat even without direct sun.
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Drinking ahead of thirst can help
During hot weather, the CDC recommends drinking fluids regularly rather than waiting until you’re desperately thirsty. Water is sufficient for many everyday situations. People sweating heavily for prolonged periods may also need to replace electrolytes, although most people don’t need sports drinks simply because the temperature climbed. Alcohol can make hydration more difficult, and people should also be mindful of excessive caffeine during significant heat exposure.
Urine color can offer a rough clue: pale yellow generally suggests better hydration than dark yellow urine, although medications, supplements and medical conditions can affect color.
The biggest mistake may be trying to tough it out
Heat illness can progress while someone keeps working, walking or exercising because they don’t want to stop. But once dizziness, weakness or nausea appears, continuing to generate body heat can make matters worse. Get somewhere cooler. Rest. Drink fluids if you’re conscious and able to do so. And seek emergency help for confusion, collapse, seizures, loss of consciousness or suspected heat stroke.
Heat doesn’t care how fit you are or how determined you are to finish what you’re doing. Sometimes the smartest thing you can do is stop.
Have you ever realized only after the fact that you’d become significantly dehydrated?
