I hope the betadine helps
but I would still recommend a vet. I notice the marks are very regular, and equally spaced. If your heating tape loops back and forth across the shelf you got hot spots under the snake. The thermostat wouldn't pick that up and cut the power because the effect is too localized. I suspect that if you look, you will find the marks on the snake correspond to the placement of the tape. The width of the heating element will probably correspond to the width of the marks. Other people have had pythons burned by UTH. Check out this thread, and look how similar your problem is. http://ball-pythons.net/forums/showt...n-death-s-door This snake is more badly burned than yours, but notice the burned scales are brown, and scale loss is evident.
To check for hotspots, move the snake to a new container. Cover the bottom of the old container with a thick bath towel for 60 minutes while the tape is on. Remove the towel and quickly scan the bottom of the enclosure with an infrared thermometer. I will bet you find hot spots.
David