I am sure the injury was from a burn. I don't think it's much of an infection, unless there's a lot more I can't see. I would put some silver sulfa cream on his wounds and be done with it - barring any sort of systemic infection. Baytril can be really rough on them, and if there is NOT systemic infection, it can do much more harm than good.
The orange looking stuff on his back is possibly his spine. Use the SSD cream and he should be fine. These things can take such trauma very well - as long as it's kept clean and a good antiseptic is applied.
You need to remove the heating bulbs from his cage and place them so that there is absolutely no place in there where the temperature is high enough to burn them. Something's been cooking his skin. A problem with chameleons and heat sources is that they will stay really close to them when the temp's cold - their internal temperature stays cool, so they move to a warm spot. BUT, due to the air being cold, their internal temp never rises, and they just sit there, heating up more and more, until their skin is cooked.
If it's cold, a heat bulb or ceramic emitter IN or near the cage can be a very very bad idea. It's best to try to find a way to heat the air in the room, else they'll cook themselves to the bone.
Looked like his front leg was swollen. Get some more pics of that if you can.
