It's no secret that having the perfect sheets on your bed can make all the difference. During Summer, most people use thin cotton fabric because it's super breathable. As the weather starts getting colder, it's smart to invest in sheets that will keep you warmer. Flannel sheets are cozy and keep you warm because they're also made from cotton, but what makes these different is that they're blended with wool, poly-wool, or polyester. Adding those thicker materials helps to lock in heat and keep you warm while sleeping. Switching to these sheets in colder times can also save you money because you might even be able to use your heater less! Shop our top picks that you'll love sleeping in this Fall.