Rave Heat and Hydration

Raves and festivals are all about expending energy and feeling good, but there's a little-known risk for extreme events: how much water is too much. too much water, dehydration, overheating—you name it, all dangerous. Here's what to watch for and when to seek help.

Heat stroke and heat exhaustion: the hotter danger

As a packed dance floor means more body heat and less air flow, the indoor temp can quickly tip into the danger zone. Heat exhaustion can come on quickly, or trail behind a full day on your feet in a hot environment.

Early heat-exhaustion warning signs include dizziness, weakness, headache, and nausea. Treating with water and moving to a cooler spot can head off worse symptoms, but a heat stroke is a medical emergency. Watch for a body temperature over 104° and for the mental-status change that distinguishes heat stroke from heat exhaustion: the person will be confused, disoriented, or unconscious, a sign that abnormal function is causing the problem, not just high heat stress.

Everyone sweats, so don't rely on "no sweat" as a heat-stroke sign. CDC warnings list hot, red skin that may be dry or damp. The key is the mental-status change coupled with a body temperature rapidly climbing above 103°, not just a faint from overheating. Even if someone feels better after cooling off, ongoing confusion, worsening mental status or extremely high temperature calls for urgent medical evaluation.

Too much plain water: hyponatremia

When sweat loses sodium and someone then drinks a lot of plain water, sodium levels in the blood drop. Result: low-sodium symptoms (usually) followed by dangerously swollen brain cells (sometimes). The headache, confusion, and weakness that can come from that are the opposite of dehydration, even if you're hot. Since hyponatremia's main symptom is altered mental status, the key is tying it to a history of the person drinking lots of water.

While heat stroke can strike almost instantly, someone drinking a lot of water may not see problems for a day.

The big difference is sweating without sodium replacement: heavy fluid intake without electrolytes. Muscles, and then brain cells, absorb water from the blood. When brain cells swell, the result is the confusion, seizures and coma that you'd treat like heat stroke if you didn't realize their source.

What to do first

Do you have a heat stroke or hyponatremia in front of you?

In both cases, stop the physical activity and call for trained medical help as soon as you can.

Keeping your fluids and your brain cool is the best defense against both risks. Find shade, drink fluids with electrolytes, stop dancing if you need to, and watch your friends.