heat

1. A high temperature; the sensation produced by proximity to fire or an incandescent object, as opposed to cold. 2. The kinetic energy of atoms and molecules, as well as rotation and vibration. 3. SYN: estrus. 4. SYN: enthalpy. [A.S. haete]

- atomic h. the amount of h. required to raise an atom from 0° to 1°C; approximately the same for all elements (about 25 kJ/g-atom).

- h. of combustion the quantity of h. liberated per gram-molecular weight when a substance undergoes complete oxidation.

- h. of compression h. produced when a gas is compressed.

- conductive h. h. transmitted by direct contact, as by an electric pad or hot-water bottle.

- convective h. h. conveyed by a warm medium, such as air or water, in motion from its source.

- conversive h. h. produced in a body by the absorption of waves that are not in themselves hot, such as the sun's rays or infrared radiation.

- h. of crystallization the quantity of h. liberated or absorbed per mol when a substance passes into the crystalline state.

- h. of dissociation the h. (expressed in calories or joules) expended in the dissociation of 1 mol of a substance into specified products.

- h. of evaporation the h. absorbed in the evaporation of water, sweat or other liquid; for water it amounts to 540 cal/g at 100°C. SYN: h. of vaporization.

- h. of formation the h. (expressed in calories or joules) absorbed or liberated during the (hypothetical) reaction in which a mole of a compound is formed from the necessary elements, in elemental form.

- initial h. the first burst of h. produced after the beginning of a muscle twitch, described by A. V. Hill.

- latent h. the amount of h. that a substance may absorb without an increase in temperature, as in conversion from solid to liquid state (ice to water at 0°C), or from liquid to gaseous state (water to steam at 100°C). Cf.:sensible h..

- molecular h. the product of the specific h. of a body multiplied by its molecular weight.

- prickly h. SYN: miliaria rubra.

- radiant h. h. given off from any body in the form of infrared waves.

- sensible h. the amount of h. that, when absorbed by a substance, causes a rise in temperature. Cf.:latent h..

- h. of solution the quantity of h. absorbed or evolved when a solid is dissolved in a liquid.

- specific h. the amount of h. required to raise any substance through 1°C of temperature, compared with that raising the same volume of water 1°C.

- h. of vaporization SYN: h. of evaporation.

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human erythrocyte agglutination test

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heat 'hēt vi to become warm or hot vt to make warm or hot

heat n

1 a) the state of a body or of matter that is perceived as opposed to cold and is characterized by elevation of temperature: a condition of being hot esp a marked or notable degree of this state: high temperature

b ) (1) a feverish state of the body: pathological excessive bodily temperature (as from inflammation) <knew the throbbing \heat of an abscess> <the \heat of the fever> (2) a warm flushed condition of the body (as after exercise): a sensation produced by or like that produced by contact with or approach to heated matter

c ) (1) added energy that causes substances to rise in temperature, fuse, evaporate, expand, or undergo any of various other related changes, that flows to a body by contact with or radiation from bodies at higher temperatures, and that can be produced in a body (as by compression) (2) the energy associated with the random motions of the molecules, atoms, or smaller structural units of which matter is composed

2) sexual excitement esp. in a female mammal specif ESTRUS

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(hēt) [L. calor] 1. the sensation of an increase in temperature. 2. the energy which produces the sensation of heat. It exists in the form of molecular or atomic vibration (thermal agitation) and may be transferred, as a consequence of a gradient in temperature, by conduction through a substance, by convection by a substance, and by radiation as electromagnetic waves. Symbol Q or q. 3. estrus. 4. to become, or to cause to become, warm or hot.