Is it safe to sleep in polyester bedsheets during hot weather?
Use caution in hot weather. Polyester can trap heat, and sweat makes treated textile contact more important.
What is in it
Polyester is a plastic fiber. It can feel hot because it does not breathe like linen or cotton. In summer, more heat means more sweat and longer damp contact with bedding.
The highest concern is polyester bedding with stain-resistant, water-repellent, wrinkle-resistant, or mystery performance finishes.
What the science says
A 2025 Science of the Total Environment study found PFAS and organophosphate esters in sampled household textiles and children's garments. Sweat increased modeled dermal absorption up to 3252-fold for PFAS and 835-fold for OPEs compared with dry contact.
A 2025 Reviews on Environmental Health article on formaldehyde-treated uniforms found that perspiring while wearing treated textiles was associated with more skin symptoms.
These studies are not polyester bedsheet tests. They support the practical point that heat, sweat, and treated textiles are a bad mix for long skin contact.
What to do
For hot weather, choose plain cotton, linen, silk, or bamboo bedding over treated polyester. Avoid stain-resistant or no-iron claims. If you are replacing one item first, start with the pillowcase because your face touches it for hours.