also salt. I don't remember: does Gatorade have sodium in it? The headaches could also be a sign of salt-depletion. On hot days I usually supplement my electro-mix with extra potassium, calcium and magnesium tablets and salt. It seems to keep the headaches away! But drink drink drink is the best thing. If you're only drinking every 12-15 miles, that's just once an hour and that just isn't enough.
On long rides I wear a Camelback that carries 100 oz of water plus 2 water bottles with Electro-Mix and 2 bottles with Electro-Mix/salt in them. I know there are roadies out there that frown on camelbacks on a road bike but
A) they can just get a life
B) I'm riding self-supported
C) I'm not riding with them anyway! so
I would strongly suggest a camelback and to drink about every 10-15 mins during your rides!
let us know how it goes for you!
PS: I did my first century in 80+ degree heat during the middle of the day with no headaches so it is doable!....just find what works for you.
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways, champagne in one hand, strawberries in the other, body thoroughly used up, totally worn out and screaming: "Yeah Baby! What a Ride!"