It's basically a wooden box with glass sliding doors at the front. Light fitting at the top 2 vents that can be closed and a pretty deep kick plate. It's wood so with the heat mat underneath theres not alot of heat coming through. It's set up with the fitting for a basking bulb at one end and the cooler spot at the other
I do have locks for the glass and there arent any cracks or holes the snake could get through other than the glass there is a gap between the 2 pieces of glass. Which I would say the snake could very easily get through. I know nothing is going to 100% be secure but if I can try an secure as best I can.

You might be surprised at how much heat goes thru. The top of my boa cage is 3/4 inch plywood with a 150 watt ceramic heat emitter inside it attached to the ceiling. The heat definately is felt on top of the outside of the cage.
In fact I just checked it with my temp gun and the wooden top is at 75 degrees at the end away from the heat emitter while directly over it the wood is reading 96 degrees.

With a bit of thought and work it CAN be 100% secure and that should be your goal. As for the space between the sliding doors, you can get a strip of acrylic or wood and silicone it in place to close that off. Get it as tight as you can with the doors still functional.

__________________
Merlin,
What's Life Without A Little Magic!

Now a thin strip of wood might be a good idea there was a piece of plastic tracking before but my iggy pulled it off when he was a baby and it didnt take much for him to do it that would say it wasnt very secure.
I think the best idea is to set it up with the heat mat underneath and test the temps

I think I've sorted it got a thin strip of wood wrapped it in felt so the glass slides easily and secured it with silicone. Set everything up with the heat pad underneath thats half the size of the viv and the other half is heated by the basking bulb and been checking the temps, basking end 88/89 cooler end with the mat 73/74 had to turn up the thermostat just slightly so I could get the right temps but its worked I'm fetching snake on wednesday and leaving everything set up so its ok for snake to go straight in.