Bamboo bedding and why it feels cool to lie in

Short answer: The sense of coolness comes from the fabric moving moisture away from the skin and letting it evaporate. Evaporation takes heat with it, and that reads as coolness.

Evaporation and not temperature

The fabric is not colder than any other fabric. It just moves the moisture away faster, and evaporation cools. See bamboo bedding.

That is why it does not work in winter

If you do not sweat, no evaporation happens, and then the fabric insulates like any other bedding. That is why it works all year.

The weave plays a part

Percale feels cooler than sateen, because the surface has less contact with the skin. The weave amplifies or dampens the effect.

Fabric softener cancels it

The film from fabric softener stops the moisture entering the fibre, and then the whole effect disappears. See washing and care.

The nightwear has to play along

If the nightwear is dense and synthetic, the moisture never reaches the sheet. Every layer has to be able to pass it on. See bamboo nightwear for men.

Frequently asked questions

Is bamboo bedding colder than cotton?

No. It moves the moisture faster, and evaporation is what cools the skin.

Does it work in winter too?

Yes. If you do not sweat, it insulates like any other bedding.

Can the effect disappear?

Yes, if you use fabric softener. The film stops the moisture entering the fibre.