Time to enclose it all

[Gocntry]

Many things work, & many materials are easy to install. Not sure I'd want to look at "foil" but the snake probably won't care if you don't. More expensive but
cork looks nice too (ie. more natural).

I have the tanks wrapped on 3 sides with black construction paper to darken the tanks / block views of other snakes sitting next to each other.

The foil insulation would go on the outside of the black paper, so it hopefully the bright foil wouldn't bother the snakes at all, then in the summer

it could be removed and leave the black paper on.