Compositions which have a physiological cooling effect, and active compounds suitable for these compositions

A method of achieving a cooling effect on human skin or mucous membrane which comprises applying to such skin or mucous membrane an effective amount of a composition comprising at least one ketal of the formula ##STR5## in which R.sup.1 represents a C.sub.2 -C.sub.6 -alkylene radical having at least 1, but not more than 3, hydroxyl group(s), and

• either R.sup.2 and R.sup.3 independently of one another represent C.sub.1 -C.sub.10 -alkyl which is optionally substituted by 1 to 3 radicals selected from the group consisting of hydroxyl, amino and halogen, or C.sub.5 -C.sub.7 -cycloalkyl, or C.sub.6 -C.sub.12 -aryl, with the proviso that the total of the C atoms of R.sup.2 and R.sup.3 is not less than 3,
• or R.sup.2 and R.sup.3 together represent an alkylene radical which, together with the carbon atom which carries the radicals R.sup.2 and R.sup.3, forms a 5-7 membered ring, said alkylene radical being unsubstituted or substituted by C.sub.1 -C.sub.6 -alkyl groups.