I'm trying to up my water intake. I drink maybe 16oz a day, if that, and a glass or two of milk and a can of diet soda.
I don't want to become dehydrated as the weather is only getting hotter, and anyways I know that you're supposed to drink at least 32-64oz a day.
But once I get past 16oz, I start to get a headache. I find this to be odd. The water I drink is either from a filtered dispenser (at work) or bottled, not tap, so I don't think it's anything IN the water that's causing it.