Slept fine in the new pajamas on two flights, didn’t get hot or sweaty. Couldn’t have said whether they’re cotton or polyester.

FWIW, White Company design has slightly changed, now navy blue pants with medium gray shirt, V notch at neck with contrast color on neck trim, small QR oryx tag on bottom of shirt. The navy color and V notch are slight changes from prior all-gray design with a stitched design at the nape of the neck.