A thermally image record material such as a secure document is taught which is susceptible to rapid and bulk destruction of confidential or sensitive information by microwave or high energy absorption. The thermally responsive record material comprises a heat sensitive composition applied onto a substrate having provided thereon in proximity, to the heat sensitive composition as a subcoat or undercoat or back side coating, a layer of particles of an energy receiver material such as a microwave susceptor. Sensitive information imprinted on the record material can be readily destroyed by microwave heating.