An Etymological Dictionary of the German Language/Annotated/heiß

by Friedrich Kluge

heiß, adjective, ‘hot, ardent, vehement,’ from the equivalent Middle High German and Old High German heiȥ; compare Dutch heet, Anglo-Saxon hât, English hot, Old Icelandic heitr; a common Teutonic adjective for ‘hot,’ pointing to Gothic *haita-; from the root hī̆t, to which Hitze is akin. This root may be extended from hī̆, with which Old High German an Middle High German hei, gehei, ‘heat’ is connected. See heizen.