The product can change from a liquid to a solid or gas with higher temperatures. It can become more viscous. Some products increase in viscosity as the become cold, others when they get hotter. It can solidify. A change in temperature is enough.
Some products solidify with heat, others with cold.
A film can build on the hot seal surface restricting movement. This can occur at the lapped faces or in-between sliding components that must be free to flex and move. The product can crystallize with a change in temperature. Vaporization at the seal faces can freeze the moisture outboard of the seal or any oil or lubricant that might have been put on the lapped faces. Hot water experiences this failure.