Polypropylene (pp) and heat: A wifi laptop is placed on a metal stand that sits on a polypropylene (pp) utility cart (rated 0-200 degrees F). The cart heats up around the perimeter. What type of heat from the computer is the cart absorbing? RF Radiation ; Heat Radiation ; ELF Radiation; or a mix of frequencies? What is the method of transfer conduction or radiation? What is happening?