I travel a lot as well. In fact, I am doing the same right now. I'll be gone next week. The best thing you can do is to have the person over at your house and show them what they have to do. Keep a list of tasks simple. Also, feed the chameleon extra of his favorite food and keep the feedings while you're gone simple -- maybe offer crickets. He'll be fine for a few days. Also, make sure you have a spare lamps, bulbs and a manual mister just in case of any failures.
I am fortunate to have a full time employee that is here everyday to take care of our child. She's now becoming an expert on reptile care, too.