Thermofoil cabinet doors are neither thermo nor are they foil. The manufacturing process of thermofoil consists of heat treatment gluing of vinyl veneer over MDF (medium density fiber) board. Deciding to use thermofoil cabinet doors is a personal choice and preference.
Thermofoil cabinet doors are inexpensive and come in many different styles. You can upgrade your kitchen with less expense. The veneer that is attached to the MDF comes in many contemporary and traditional styles as well as modern and post-modern colors and textures. If you want to have a beautiful new look to your cabinets for low cost thermofoil cabinet doors may be the best decision. If a heat shield is installed near your oven or range it will help reduce heat damage.
The finish, being vinyl, has the potential to experience adverse effects due to heat. The adhesive that holds the veneer is heated so any heat that it is exposed to will have adverse effects and cause the vinyl to separate from the MDF. Additionally, the vinyl can discolor after just a few years changing the entire look of the cabinet. The closer to the heat source the more change the veneer will experience. This causes your cabinets to lose consistent look throughout your kitchen.