Some embodiments of the invention provide an electronic safety device, adapted for use in a helmet suitable for an impact-sport, which operates to warn a first participant that a head inside the helmet is in an unsafe position relative to a body coupled to the head. In some embodiments, the head may belong to the first participant, in which case the first participant is warned of their own unsafe head position. Alternatively and/or additionally, the head may belong to a second participant, in which case the first participant is warned of the unsafe head position of the second participant. In very specific embodiments the electronic safety includes a sensor that senses head position and provides corresponding readings, and a processor that interprets the reading of the sensor in order to determine whether or not to produce a signal that indicates that the head is in an unsafe position.