Keeping cool in the heat

[Dakota]

Quoted from wikipedia...

Endurance sports
Marathon runners are susceptible to water intoxication if they drink only water while running. Although sweat is relatively hypotonic compared with body fluids, marathon runners perspire heavily for long periods, potentially causing their sodium levels to drop when they consume large amounts of fluids to quench their thirst. The replacement fluids may not contain sufficient sodium to replace what has been lost, and this puts them at high risk for water intoxication. Medical personnel at marathon events are trained to immediately suspect water intoxication when runners collapse or show signs of confusion.

Overexertion and heat stress
Any activity or situation that promotes heavy sweating can lead to water intoxication when water is consumed to replace lost fluids. Persons working in extreme heat and/or humidity for long periods must take care to drink and eat in ways that help to maintain electrolyte balance. Even people who are resting quietly in extreme heat or humidity may run the risk of water intoxication if they drink large amounts of water over short periods for rehydration.

• On September 12, 1999, US Air Force basic trainee Michael J. Schindler died of heat stroke, severely complicated by water intoxication, two days after becoming seriously ill during a 5.8 mile march. The Air Force changed its recruit training procedures as a result.
• Other notable fatalities due to water intoxication include Andy Warhol, Anna Wood, 2002 Boston Marathon competitor Cynthia Lucero, and Washington, D.C. police officer James McBride.