I suggest a hide that he can fit into on both sides of the cage. The hide should not be so big that he feels like a lone player in a soccer stadium, but should be a size where he can fit snugly where he is able to touch the sides with his body (kinda like a dog in a doghouse).

Also, placing the water dish under the radiant lamp can help raise humidity. If you have a mesh top cage then seriously consider covering at least three quarters of it to retain humidity and maintain a supply of airflow (I cover mine with thin laminated plywood)