Direct heat can quickly damage your laminate countertop. Remember, laminate countertops are essentially plastic, and plastic melts easily. Even relatively cool pans can deform a laminate countertop, because plastic does not have enough structural integrity to withstand even relatively low cooking temperatures. Damage from direct heat is usually irreversible, and worse, burns and melting are seldom covered by warranty since they result from misuse.
How construction affects heat resistance
Laminate countertops are normally made by gluing the laminate onto the surface underneath, without exposing the material to heat. This makes them unconditioned and weak against heat.
Higher-end laminate countertops often use fiberglass as the laminate, and detailed plastic is used as the substrate or filling. These two are usually heated, causing them to melt into each other and creating a single-piece countertop. Such countertops offer more resistance against heat, but they still have a lower heat threshold compared to stone or ceramic countertops.
The construction also affects the way the damage will happen. With fiberglass laminates, heat from a pan will cause the laminate material to peel away from the substrate. The laminate chips away from the surface material, and sometimes comes away in strips. Glued laminates are more brittle. The heat will usually melt the adhesive, and the laminate comes away as a single, solid piece.
Manufacturers of laminate countertops are aware of their products' weakness against heat. While some find ways of improving heat resistance, such as applying a lacquer or glaze coating, they still recommend using a trivet or an insulated heating pad to keep hot pans off plastic surfaces. Some manufacturers claim that their products can withstand temperatures of over 200 degrees Fahrenheit. These usually refer to isolated cases. Repeatedly placing a hot pan on a laminate countertop will eventually dislodge the laminate.
Manufacturers also recommend allowing pans to cool for at least an hour before placing them on laminate countertops. If you want to save time, you can also immerse the bottom few inches in cool water, which should shave a few minutes off your waiting time.