Don t wait until you are thirsty. When you get into a dehydrated state you are weak, dizzy, profoundly exhausted and can have problems thinking clearly. Feeling nauseous, being drenched in sweat, dark urine with a strong odor, and having cramps are also warning signs of dehydration. Drinking lots of fluid with some a small amount of salt helps treat early dehydration. Severe dehydration requires medical attention, typically IV fluids are given.
Heat exhaustion is the next step beyond simple dehydration.
Because of a large loss of body fluid, the circulatory system can collapse, causing a sudden drop in blood pressure, which can lead to unconsciousness. Because heat exhaustion is the next step past dehydration, it gives a lot of warning signs before its onset. Increasing fatigue, severe cramps, weakness, inability to think properly or strange behavior, drenching sweats, dilated pupils, and nausea are all warning signs of heat exhaustion. A person with more severe heat exhaustion can have cold, pale, clammy skin, be agitated or disoriented, and can complain of profound thirst. Heat exhaustion is a serious medical condition.