This room was kept hot. The walls are painted to appear as a luscious outdoor grassland- green and plenty- a start contrast to the actual savanna that now exists outside of the temple. The ceiling is also painted bright yellow and blue- the color of sky and sun. The paint on the ceiling glows softly and radiates heat; giving this room an unnatural comfort to desert-dwelling peoples and animals. In the many centuries the paint has faded and chipped, leading to a comfortable though still above-average temperature compared to the rest of the temple.
If you break off bits and mortar of the ceiling here you can carry it around as a heat source. If anyone in the party is a skilled alchemist; a thinner could peel the paint off and potentially let you paint it on something else; making even the thinnest garments or walls winter-proof.
There's no treasure in this room, but it would be great to take a nap in.