Usually they don't have any filter, so they can work at night on the IR spectrum. A baseball cap with a string of SMD LEDs on the edge should do the trick, at l

Usually they don't have any filter, so they can work at night on the IR spectrum. A baseball cap with a string of SMD LEDs on the edge should do the trick, at least at night. During the day, a cap and a surgical mask will do it. If you go indoors, remove the mask and keep your head low, since most cameras are on the roof.