An electric heat therapy instrument has an electric ampere controller 1 connected by two outside electric wires 2 to a 110-v electric outlet. The handle tube 3 is joined in its inferior extreme to a heating tube 9. A 110-v, 20-w bulb 6 is putting on the bulb socket 5 inside of the heating tube 9. To conserve the heating tube 9 temperature level and avoid the heat expansion to the handle tube 3, I invent a technique to cut the expansion of the heat in a metal material, it consists in making horizontal and round holes 7 around the top of the heating tube 9.