The W band of the microwave part of the electromagnetic spectrum ranges from 75 to 110 GHz, wavelength ≈2.7–4 mm.
A number of passive millimeter-wave cameras for concealed weapons detection operate at 94 GHz.
Less-than-lethal weaponry exists that uses millimeter waves to heat a thin layer of human skin to an intolerable temperature so as to make the targeted person move away.
A two-second burst of the 95 GHz focused beam heats the skin to a temperature of 130 °F (54 °C) at a depth of 1⁄64 of an inch (0.40 mm).
The United States Air Force and Marines are currently using this type of Active Denial System.