Sleep temperature, in general, is very subjective to the individual. Some people feel no difference in body temperature when sleeping on memory foam, others do. This includes gel memory foam products as well. While not all cooling gel products are alike, our pressure-activated phase-changing gel surface material (AquaCHILL and BioFROST for example) has an instant, cool-to-the-touch characteristics due to the nature of the chemistry. The degree or coolness varies by product and will also depend on other ancillary characteristics of the product, such as breathability of the materials, or cooling fabrics (ActiveCHILL) used on the covers. Although gel products (i.e.: gel memory foam, gel overlay, gel glaze, gel beads, etc.) are classified as a cooler material, sleep temperature varies by the individual and the coolness is very subjective to the user. Using a sheet set with a high thread count (greater than 250 TC) will diminish the cooling properties as well. We suggest using a low thread count sheet set on any product that has cooling properties.