I would suggest that you gradually build up to riding in the heat. This will acclimate you to riding such a long distance in those conditions.

I also recommend that you work up to riding a metric century (62.5 miles approx) in the next month. By doing this distance and training for heat, you will find out #1- how your body feels on the bike for a long distance #2- what you need to eat and drink to keep hydrated and energized.

Re food and liquid- I'd experiment with different kinds of sports drinks besides Gatorade to see which one agrees with you the best. Also, get some electrolytes (E-Caps) Hammer Nutrition-www.e-caps.com. These will help you in the heat. Hydration is a major factor when riding in heat and humidity. Some of us did a ride last weekend (see California thread - Mines Road Recap)in 95 degree weather. I took the E-caps and lots of liquids and managed to get through it without cramps. Jelly Belly has sports beans that you might want to try also. (I take both with me on all of my rides)

Another factor is clothing- for a century ride, you'll probably want gel chamois shorts made for women. You can pick those up at most bike stores- Performance Bikes has great gel shorts, for example. And...... be sure to have some chamois butter. That's a life saver on long, hot rides!

The more metrics you can get in the better!!!! Once a week will really build your endurance.

Hope this helps!