Nylon is typically warmer than polyester and can be sweatier or stick to the body more. Nylon, the warmer fabric, adheres to the body more than polyester. In any case, nylon stays close to the body, and the tighter it is, the less breathable it is. Polyester, on the other hand, has a limited ability to breathe and is not as warm as nylon.

Comfort wise, both nylon and polyester are light-weight, quick-drying and smooth. Nylon tends to be warmer than polyester, and can often be more sweaty or cling more to the body.

Because nylon clings more to the body than polyester does, nylon is seen as the warmer material. The closer to the body the less breathable the fabric or so the principle goes. Nylon remains very close to your body no matter what you are doing.

Polyester has good insulation properties, keeping you warm in cold weather. It also dries quickly, so you don’t feel clammy or chilled when sweating. Nylon, on the other hand, is known for its breathability, allowing air to circulate and preventing overheating.

Polyester is better at keeping you warm than nylon because it traps air inside it, which acts as insulation against cold temperatures. Nylon doesn’t do this as well as polyester so it’s not suitable for use in extreme temperatures or conditions like skiing or hiking where you need extra warmth from clothing.