The instant invention refers to the use of a concentrated aqueous polymer dispersion with an average particle size of less than 1000 nm comprising (a) a polymer carrier prepared by heterophase radicalpolymerization of at least one ethylenically unsaturated monomer in the presence of (b) an oil-soluble organic UV absorber selected from the class of p-aminobenzoic acid derivatives; salicylic acid derivatives; benzophenone derivatives; diphenyl acrylate derivatives; benzofuran derivatives; polymeric UV absorbers, comprising one or more organosilicon radicals; cinnamic acid derivatives; camphor derivatives; s-triazine derivatives; trianilino-s-triazine derivatives; menthyl anthranilates; and benzotriazole derivatives; wherein the weight ratio of the oil-soluble organic UV absorber (b) to polymer carrier (a) is greater than 50 parts UV absorber per 100 parts of carrier; for the protection of human and animal hair and skin against the damaging effect of UV radiation. The concentrated aqueous polymer dispersions show unexpectedly high sunscreen effects and a positive skin feeling.