Sea to Summit says:
A climate control travel liner specifically designed for warm or humid conditions. The Coolmax Adaptor, as the name suggests, is a liner that adapts to varied temperatures and humidity because it is made from Coolmax, a proven moisture management fabric, giving you a more comfortable night’s sleep. Now also available in our popular “Traveller” shape with pillow insert, it comes with and packs down into its own 8 x 13cm UltraSil stuff sack.
Coolmax is well known to wick moisture away from the skin leaving the wearer cool and dry - this sleeping bag version will do the same while you rest.Could be used on its own if camping in a warm climate.