Does microwave radiation linger inside a microwave oven? General Physics discussion And what about the materials used to shield microwaves, do they use lead, copper Kenmore Oven/Microwave Combo Heat Shield; Kenmore Range/Stove/Oven Heat Shield; Montgomery Wards Range/Stove/Oven Heat Shield; Tappan Oven/Microwave Combo Heat Shield A microwave oven to shield chicken wings from overcooking) as long as the foil doesn't touch the sides of the oven. Always supervise children when they use the microwave