Burns to breast reconstructions, both autologous and implant-based, are well described in the plastic surgery literature. The mechanism has often been contact; however, burns secondary to sun exposure have also been reported. With the increasing number of prepectoral breast reconstructions, including irradiated prepectoral reconstructions, we would like to highlight the increased susceptibility of these reconstructions to thermal and ultraviolet injury. We present the case of a patient who underwent prepectoral implant-based breast reconstruction years after irradiation, who subsequently developed full-thickness injury to her mastectomy flap after minor sun exposure. After weeks of daily wound care and hyperbaric oxygen treatments, the patient eventually reepithelialized over her exposed acellular dermal matrix tissue layer, allowing for implant salvage. Postmastectomy flaps overlying implants in the prepectoral plane are delicate; major burns can develop from minor thermal injury, even months after surgery. Irradiated prepectoral reconstruction patients should be educated about the susceptibility of their breast flaps to even minor burn injury and should maintain vigilance beyond the immediate postoperative period. It remains to be seen whether prepectoral reconstruction in an irradiated breast can be a viable, long-term option.