Provided are compounds of formula (I) wherein m is 0, 1 or 2; R1 is a mono- or bicyclic heterocyclic ring system including one, two or three heteroatoms selected from nitrogen, sulphur and oxygen; R2 is selected from hydrogen, methyl and ethyl; I) R3 is hydrogen, methyl, or ethyl; and R4 and R5 are independently selected from ethyl and isopropyl; and R3, R4 and R5 together have at least 6 carbon atoms; or II) any two or all of R3, R4 and R5 form together with the carbon atom to which they are attached 3-para-menthyl, bornyl, or adamantyl; having cooling properties, their use as cooling agent and compositions including them.