You certainly can make a glass tank, heat light and screen lid work perfectly fine, you just have to take steps to make the enclosure work... I have a giant 50 gal tank with a screen lid that i heat using a 100w infared bulb on a dimmer and measure everything with digital thermo/hydromometer.... Start by cover your entire screen top then on one end cut out a whole slightly bigger then the hood of the light. next on the opposite end cut out a rectangular opening, size and location of these holes will depend on your tank so youll have to experiment to get your locations correct, next youll need as big of a container for water as you can fit, i use 1gal ice cream buckets i cut down so the snake can easily get in and out along with a hide under the heat source, the water should evaporate over time and raise humidity in the enclosure.