Burning with embarrassment, I hobbled along the ridgeline until the next checkpoint, where a Presidio employee explained my problem: I wasn't drinking nearly enough water.

FORBES: Pain is good

Simply finding enough drinking water can be a tactical challenge on a 35-mile run through the mountains.

FORBES: Hypothermia for Fun and Profit

The contraption was intended to treat 4 gallons per minute, enough to provide drinking water for 2, 000 people.

FORBES: Running Dry

The contraption was intended to treat 15 liters a minute, enough to provide drinking water for 2, 000 people.

FORBES: Magazine Article

The water released over these two days would be enough to supply all of Tyneside with drinking water for a fortnight.

BBC: Hundreds of salmon die in heat

Drinking several litres over a relatively short period of time could be enough to cause water intoxication.

BBC: Why is too much water dangerous?