What is the best fabric for bed sheets to stay cool?

The best material I've found for night sweats are natural fibers like cotton and linen, particularly cotton percale, since it gently drapes over the body and allows for more air movement underneath, which in turn helps sweat to evaporate more quickly.

Fans of silky, satin fabrics may find percale sheets too textured, but I highly recommend anyone who sleeps in a warm place to try these sheets - what they lack in silkiness and smoothness, they more than make up for in softness, breathability and durability. If you don't know where to find them, I can share a link - soft cooling sheets for queen beds, you'll definitely find them there.