The present disclosure relates to a cosmetic composition comprising, in a physiologically acceptable medium, at least one compound which gives the cosmetic composition a thermal profile having a melting peak wherein the mid-height width Lf is less than or equal to 20° C., and wherein the composition is heat-stable. The present disclosure also relates to the process of depositing a film on the keratin fibers, wherein the film is homogenous and/or has improved curling properties, comprising applying the cosmetic composition disclosed herein to keratin fibers.