IMHE, as long as temperatures are in the right neighborhood and the animal has access to sun as well as full shade it can remain outdoors. I stress the importance of access to full shade though. Objects, including chameleons, exposed to the sun can rapidly reach temperatures well above ambient. For instance, a chameleon (or many other objects) kept in full sun can reach lethal temperatures >100 F (>38 C) on a 75 F (24 C) day.