The type of fabric used in your bedding can significantly influence your warmth levels. Natural materials such as cotton and flannel are breathable yet retain heat better than synthetic fabrics. A flannel sheet set can make a notable difference in staying warm, as its brushed texture feels soft against the skin while providing excellent insulation. Additionally, consider wool or fleece blankets to be thrown over your sheets or comforters, as they offer a luxurious warmth without the need for electric heat.