Paint your walls white.

Clare Fresh Kicks Paint, $54 at clare.com

Three experts told us that lighter paint colors are a great way to keep a space cool. Interior designer Ariel Okin says, “Less pigmented paint colors

reflect light and don’t absorb heat, which makes cool-toned hues a good choice for walls.” All three recommend paints from online start-up Clare,

including its “Snow Day,” “Frozen,” and “Headspace” colors.