High temperature sterilizable adhesive articles

A sterilization indicator comprising:

• a first substrate with a first major surface and a second major surface, wherein the second major surface comprises a compartment containing a fusible indicator material, and a channel in contact with the compartment for a molten indicator material to flow, and a wicking material in contact with the channel;
• a second substrate with a first major surface and a second major surface, wherein the second major surface comprises a transparent segment aligned to overlay the wicking material;
• and
• a high temperature sealing pressure sensitive adhesive layer in contact with at least a portion of the second major surface of the first substrate and the first major surface of the second substrate,
• wherein the pressure sensitive adhesive layer comprises a (meth) acrylate-based pressure sensitive adhesive matrix and a high temperature sealing agent, the high temperature sealing agent is essentially unreactive with the (meth) acrylate-based pressure sensitive adhesive matrix at ambient temperature and reacts with the (meth) acrylate-based pressure sensitive adhesive matrix at temperatures of at least 121° C. to form a heat-sealed adhesive bond, and the heat-sealed adhesive bond has increased adhesion compared to the bond of the pressure sensitive adhesive layer without the high temperature sealing agent.