A soft clean cotton flannel cloth is ideal for this purpose.
Pack of four large natural color, organic cotton flannel handkerchiefs... perfect for those who like more traditional sized hankies.
In general, lightweight cotton weaves are the coolest, cotton flannel is a little warmer and synthetics such as polyester are the warmest.
On the other hand, if you desire bedding which will make you feel warm and cozy, then cotton flannel bedding or woolen fabrics would be better.
A less-expensive choice is the Bumpkins Natural Receiving Blanket, made from organic unbleached cotton flannel and edged with satin.