[cpayne5]

Originally Posted by Mattyk72

I've heard of it being an issue with athletes drinking too much water too quickly when they are dehydrated.

Water intoxication - Wikipedia, the free encyclopedia

You also hear the obligatory news stories on it every year when some kid trying to join a frat dies due to it being one of the initiation duties.

Such as...
CHICO / Fraternity pledge died of water poisoning / Forced drinking can disastrously dilute blood's salt content