Don't change much from your prior racing experiences, especially two days before the race. I've done the race 5 times and a bunch of other IM races, some very hot. I always drink the same drink, Gatorade on the course and water. I just make sure I am getting enough sodium/hour. I'll do some thermotabs or base salt or some other type of tablet and chase with water.

Nutrition is a bar or two during first hour or two and then usually switch to GU or whatever they are handing out.

I pretty much drink the same amount if it's fairly warm, typically about 24oz/hour of fluid.

Don't get behind on fluids and don't over drink either, which can be just as bad.

My goal and I stress it's my plan is 400 cal/hour and a gram of sodium/hr.