KOOLFEVER is ready to use as it is when adult becomes feverish. Chill the cooling gel sheets into refrigerator for a better cooling sensation. Adhesive cooling gel sheets that is well fits onto adult’s forehead stays well in place even when user turns in bed. Crisp and cool effect persist for whole night time up to 8 hours. The moisture contained in the gel absorbs and releases heat so that specifies cooling effects are obtained (gel is water-soluble polymer based).