Gel mattresses aim to offer a cooler sleep experience, which can raise the price-point compared to regular foam mattresses. Gel foam is a good option for sleepers who like the pressure-relieving, motion-isolating feel of memory foam or polyfoam but don't like sleeping hot. Because gel must be added to either memory foam or polyfoam, gel mattresses may not be attractive to shoppers who prefer natural materials or those who are sensitive to off-gassing smells.