An electronic device designed to be used to monitor the conditions of a specific environment. It may be used to monitor environmental parameters such as air temperature, relative humidity, or atmospheric oxygen concentration. This device, designed as a cable/lead with a sensor at the distal end and a connecting plug (e.g., a jack plug) at its proximal end, is used with a parent device that requires environmental monitoring, e.g., an infant incubator, or with a dedicated monitoring device.