When you offer minimal husbandry like that (Don't get upset, I use racks which are just as minimal) you should offer an area for the snake to escape hot, dry conditions. Making sure the top is tight and does not allow heat and humidity to escape and offering a small humid hide on the cool end will help your snake thermo-regulate better and will allow you snake to maintain its water intake. Reptiles, especially from arid regions, have evolved to conserve the moisture it takes in from its prey or other sources. The cool, humid hide will allow your snake to conserve instead of having to replenish all the time.