Abstract: The device to monitor distance between people measures a pre-defined distance between a first person and other persons, and alerts the user when the pre-defined distance has been breached or violated for more than a pre-determined time. Intended to protect a first human from the deleterious effects of radiation (nuclear) associated with a second human, but useful in other circumstances, the device is designed to detect the presence of a first person within a protective radius of one to two meters of a second person by pairing the combination of one heat sensor with one distance sensor. In the event the first person is within that radius for the predetermined time, the device will alert the user of that circumstance. Alert feedback mechanisms can include an acoustic audible signal, a visible signal, a vibratory signal, or phone notification.