Abstract: A collapsible pop-open solar heating system having a heating enclosure with an open configuration and a collapsed configuration. The enclosure is made of substantially opaque flexible fabric having reflective interior surfaces, and it includes a region of transparent flexible material for the passage of light. When placed in an open configuration, the enclosure is shaped so as to reflect and focus light into a focal region in the interior space defined by said enclosure. To facilitate rapid erection, preferred embodiments include a collapsible flexible spring frame contained within at least one sleeve in the fabric enclosure. The sleeve confines the spring frame and when the enclosure is unrestrained, the spring frame urges the enclosure into an open configuration. A door in the enclosure permits placement and removal of heating and cooking vessels in the enclosure.