I have to agree - it doesn't happen as often as people like to think.
Yes, it was an issue for me, but I was working outside in the desert sun for literally 6 hours straight when it was summer and temps were in the 110+ range for weeks straight. I was only drinking when I was thirsty, but that still ended up being a couple of gallons during the course of the work day.
I would end up with a migraine at the end of the day, but drinking just a single serving of coconut water in the middle of the day fixed it.
My sorely neglected blog - http://ThatWriterBroad.com