thermo-, therm-, thermi-, -thermia, -therm, -thermal, -thermic, -thermias, -thermies, -thermous, -thermy

(Greek: heat, heating, heater, hot, warm)

The term heat is employed in ordinary language in different senses. Some scientists distinguish four principal applications of the term:

  1. Sensation of heat.
  2. Temperature, or degree of hotness.
  3. Quantity of thermal energy.
  4. Radiant heat, or energy of radiation.

thermal limit
The maximum amount of power which a transmission line can carry without suffering heat-related damage to line equipment, especially conductors.
thermal mass
A material used to absorb, store, and later release heat, and so retarding the temperature variation within a building space; for example, concrete, brick, masonry, mortar, rock, water, or any other such materials with high heat capacities.
thermal neutrality
A condition of the thermal environment of a homeothermic animal in which its heat production (metabolism) is not increased either by cold stress or by heat stress.
thermal pollution
An excessive raising or lowering of water or air temperatures above normal seasonal levels caused by industrial processes or other human activities.
thermal pollution
The release of heated fluids into a body of water, that results in increased water temperature that is harmful to the environment.
thermal power plant (s) (noun), thermal power plants (pl)
A generating facility that uses heat to produce electrical power: Thermal power plants produce electric energy from steam that has been released by water when raised to a high temperature which then spins a steam turbine that drives an electrical generator.

As with other related "plant" references, this entry is believed to be linked to the action of pressing on a shovel, or some other planting device, with the "sole of the foot" in order to work the soil for planting.

thermal radiation
1. The emission of energy in the form of heat.
2. A process by which energy is emitted by a warm surface.

The energy is electromagnetic radiation and so travels at the speed of light and does not require a medium to carry it.

3. The energy radiated by solids, liquids, and gases as a result of their temperature.

Such radiant energy is in the form of electromagnetic waves and covers the entire electromagnetic spectrum, extending from the radio-wave portion of the spectrum through the infrared, visible, ultraviolet, x-ray, and gamma-ray portions.

thermal tide
A variation in atmospheric pressure as a result of the diurnal differential heating of the atmosphere by the sun; so-called in analogy to the conventional gravitational tide.
thermal vapor compression (TVC) (s) (noun), thermal vapor compressions (pl)
A process used to remove salt from seawater, by evaporating it through a fine mesh filter that traps the brine particles so that the fluid can then be condensed into a relatively salt-free solution.
thermaldilution, thermal dilution
1. A technique used for measuring the size of a fluid-filled cavity by injecting a very cold sample of known volume and by measuring the change in temperature of the whole, assessing the degree of thermodilution, and hence the total volume of the cavity.
2. A method of cardiac output determination.

A bolus (intravenous injection of a solution) of known volume and temperature is injected into the right atrium, and the resultant change in blood temperature is detected by a thermistor previously placed in the pulmonary artery with a catheter.

thermalgesia, thermoalgesia (s) (noun) (no pl)
High sensibility to heat; pain caused by a slight degree of heat: When the ligaments, tendons, and muscles swell due to heat or hot weather, it is referred to as thermalgesia. A person is dehydrated and the joints lose water or fluids.

Thermalgesia is a condition in which the application of heat produces pain.

thermalgia, thermoalgia, causalgia (s) (noun); thermalgias; thermoalgias; causalgias (pl)
A condition marked by sensations of intense burning pain: Thermalgia is a feeling of an extreme fiery pain which is sometimes experienced following nerve injuries.

Thermalgia is a persistent severe burning of the skin, usually following a direct or an indirect trauma to a sensory nerve, accompanied by cutaneus (skin) changes.

thermality, thermally
A thermal condition; in a thermal manner, by means of or with regard to heat.
The process of reducing the kinetic energy of neutrons by repeated collisions with other particles to approximately the thermal energy of atoms of the medium in which the neutrons are undergoing elastic scattering.

The energy of the atoms is thermal in origin and neutrons with reduced energies are termed thermal neutrons.

thermalize (verb), thermalizes, thermalized, thermalizing
1. To modify temperatures so they can be applied when necessary: James thermalizes the heat in his residence during the winter so he and his family can live in warm conditions and not get too cold.
2. To achieve a heat equilibrium with the environment: A substance, as with water, is used to slow down, lessen, or thermalize the velocity of the fast neutrons in a nuclear reactor and therefore intensify the probability of fission, or of the splitting of the massive nucleus into tinier nuclei.

Quiz You can find self-scoring quizzes over many of the words in this subject area by going to this Thermo- Vocabulary Quizzes page.

Related "heat, hot" word units: ferv-; pyreto-.

Related "bubble" word unit: ebulli-.