Heat (ht), n. [OE. hete, hÊte, AS. htu, hto, fr. ht hot; akin to OHG.
heizi heat, Dan. hede, Sw. hetta. See Hot.] 1. A force in nature which
is recognized in various effects, but especially in the phenomena of
fusion and evaporation, and which, as manifested in fire, the sun's
rays, mechanical action, chemical combination, etc., becomes directly
known to us through the sense of feeling. In its nature heat is a mode
of motion, being in general a form of molecular disturbance or
vibration. It was formerly supposed to be a subtile, imponderable
fluid, to which was given the name caloric.
As affecting the human body, heat produces different sensations, which
are called by different names, as heat or sensible heat, warmth, cold,
etc., according to its degree or amount relatively to the normal
temperature of the body.
2. The sensation caused by the force or influence of heat when
excessive, or above that which is normal to the human body; the bodily
feeling experienced on exposure to fire, the sun's rays, etc.; the
reverse of cold.
3. High temperature, as distinguished from low temperature, or cold;
as, the heat of summer and the cold of winter; heat of the skin or body
in fever, etc.
Else how had the world . . . Avoided pinching cold and scorching
heat!
Milton.
4. Indication of high temperature; appearance, condition, or color of a
body, as indicating its temperature; redness; high color; flush; degree
of temperature to which something is heated, as indicated by
appearance, condition, or otherwise.
It has raised . . . heats in their faces.
Addison.
The heats smiths take of their iron are a blood-red heat, a
white-flame heat, and a sparkling or welding heat.
Moxon.
5. A single complete operation of heating, as at a forge or in a
furnace; as, to make a horseshoe in a certain number of heats.
6. A violent action unintermitted; a single effort; a single course in
a race that consists of two or more courses; as, he won two heats out
of three.
Many causes . . . for refreshment betwixt the heats.
Dryden.
[He] struck off at one heat the matchless tale of "Tam o' Shanter."
J. C. Shairp.
7. Utmost violence; rage; vehemence; as, the heat of battle or party.
"The heat of their division." Shak.
8. Agitation of mind; inflammation or excitement; exasperation. "The
heat and hurry of his rage." South.