Well, he doesn't smell like a wookiee at least.
As for the H20 part, you are both correct. Alcohol is the worst possible thing to drink when it is hot as alcohol is thinner than water and thins the blood rather than rehydrating it. Coffee is water, so to is tea (I prefer iced tea to the yucky water). The caffeine is a diuretic, but it only forces the body to expel wastes more quickly rather than allowing them to remain in. It is not the best thing, but it is also not unhealthy as long as you throw in some water.
Oh, and gatorade is great but be sure to either water it down or drink 3:1 water otherwise the salt will make you swell like a Gamorean.