Heat-activatable siloxane-based adhesive articles include a substrate and a heat-activatable adhesive layer that includes a hot melt processable siloxane-based elastomeric polymer. The siloxane-based elastomeric polymer is a urea-containing segmented copolymer or an oxamide-containing segmented copolymer. The adhesive layers are substantially free of tackifying resins and are non-tacky and non-adhesive until heated to a temperature of at least 50 C. The adhesive layers may be optically clear and may have a microstructured surface.