Coolant compositions

A coolant composition comprising an effective amount of a ketal of the formula ##STR6## 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) 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 comprising hydroxyl, amino and halogen, C.sub.5 -C.sub.7 -cycloalkyl, 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 and a secondary coolant component selected from the group consisting of menthol, carboxamides, and mixtures thereof.