New breakthrough OPX technology now included. FeverWarn is the only US-made self-service temperature scanning system with OPX scanning technology, which optimizes temperature scanning performance in varying weather conditions and doubles the range of temperature bandwidth over most forehead temperature scanners. Simply place your wrist, fist or the underside of your forearm under the scanner(1-4 inches away), and FeverWarn’s OPX scanners will detect a fever via a buzzer and screen display. Thousands of installations nationwide validate that this technology works. It’s the only self-service scanner to offer multiple ways of communicating with or activating auxiliary devices.