Polyester is thought to be a tricky fabric to care for.
Using too much heat causes damage, including shrinkage and melting.
Air dry your polyester out of direct sunlight and away from heat. Always follow the care instructions on the label.
You should not wash polyester in hot water. Polyester is a synthetic or man-made fiber derived from petroleum. Any form of heat, either water or from a dryer, will make polyester melt.
The most important step is to check the care label. This will provide you with individual guides to each item, from what setting to wash polyester on in the washing machine to times you need to hand wash polyester. This is especially helpful for items which are not 100% polyester.