Natural fabrics, such as cotton, linen and wool have higher burn temperatures, and they char instead of melting when exposed to flame. When a fabric melts onto skin it is difficult to remove, unlike a material that chars. Nomex is used for fire-resistant clothing. Wool is a good all-around fabric. Cotton and linen are best for hot weather and worst for cold, wet weather. Synthetics can be about the same as wool in the winter; many of them are fire hazards. Fabrics can be treated to help reduce their disadvantages.