Articles containing thermoplastic, thermoplastic composite or thermoplastic-clad materials are made less susceptible to heat distortion by coating the article with a two-part aqueous coating composition whose first part contains a waterborne active hydrogen-functional latex binder and whose second part contains a water-dispersible polyisocyanate. One or both of the first and second parts contain non-infrared-absorptive colored pigment. A mixture of the first and second parts coated atop a vinyl substrate cures to form a vinyl-adherent, infrared-reflective colored protective film.