The utilization of heat in the manufacturing of footwear may be accomplished through microwave energy. The microwave energy is conveyed to the footwear components through a microwave transparent window of a tool. The microwave transparent tool window forms as least a portion of a part-contacting surface of the tool. Another surface of the tool is formed from a microwave reflecting material, such as aluminum. The footwear component(s) are exposed to microwave energy while within the tool such that the microwave energy passes through the tool window to cause a dielectric heating of one or more materials within a tool cavity of the tool.