A device for regulating body temperature includes a case with an opening in the base, a plate made of highly thermally conductive material with a complementary shaped protrusion at the opening and that is inserted therein, at least a Peltier cell, an electronic circuit board for managing the functions of the device, a heat sink, a display, a battery to power the electronic circuit board, the Peltier cell and the display, a temperature sensor to measure the temperature of the skin at the surface of the case and of the plate that is in contact with the skin, a strap which is secured to said concave case, a lid for closing said case, and at least one command button operatively connected to the electronic circuit board.