The ornamental design for a heatingelement for neck warmer, as shown and described.
FIG. 1 is a front elevation view of a heating element for neck warmer, wherein the length of the USB connector cord is abbreviated;
FIG. 2 is a rear elevation view of a heating element for neck warmer, wherein the length of the USB connector cord is abbreviated;
FIG. 3 is a right side view of a heating element for neck warmer, wherein the length of the USB connector cord is abbreviated;
FIG. 4 is a left side view of a heating element for neck warmer, wherein the length of the USB connector cord is abbreviated; and,
FIG. 5 is a top plan view of a heating element for neck warmer, wherein the length of the USB connector cord is abbreviated, the bottom plan view being a mirror image.