1. Relating to or involving heat or heat transfer.
2. A localized air current that rises aloft when the lower atmosphere is heated enough to produce an instability over a certain area.
3. A rising current of relatively warm air, used by gliders and birds to gain height.
4. In meteorology, a localized air current that rises aloft when the lower atmosphere is heated by the earth’s surface enough to produce an absolute instability over a certain area; a common source of low-level clear-air turbulence.
5. Of, pertaining to, or of the nature of hot springs; of a spring, etc., (naturally) hot or warm; also, having hot springs.
6. Of or pertaining to heat; determined, measured, caused, or operated by heat.

1. The quantity of heat required to raise the temperature of one pound of water from 60 degress to 61 degrees Fahrenheit (3.9 C to 4.4C) at a constant pressure of one atmosphere.
2. The quantity of heat equal to 1/180 of the heat required to raise the temperature of one pound of water from 32 degrees to 212 degrees Fahrenheit at a constant pressure of one atmosphere, equal to approximately 1055.056 joules.

A joule is the International System unit of energy or work, equal to the work done when the application point of one newton force moves one meter in the direction of application. Symbol J [Named for the British physicist James Prescott Joule, 1818-1889, noted for his research on the mechanical equivalent of heat].

The part of the thermal conductivity resulting from the transfer of thermal energy by means of electrons and holes (mobile vacancies that act like positive electronic charges with positive masses).

One of the various techniques for extracting energy from the vertical temperature difference in the oceans: In principle, ocean thermal energy conversion can be used to generate electricity, desalinate water, support deep-water mariculture, and provide refrigeration and air-conditioning.

The temperature difference between warmer surface waters of the ocean and colder deep waters, whereas the deep waters are about 20-50 degrees Fahrenheit colder that the surface waters: In principle, the ocean thermal gradient can be utilized with various types of ocean thermal energy conversion systems.

Describing a photovoltaic system that, in addition to converting sunlight into electricity, collects the residual heat energy and delivers both heat and electricity in usable form.

The conversion of the radiant energy from the sun into heat, which can then be used for such purposes as space and hot water heating, industrial process heat, or power generation.

Solar thermal energy can be used for such applications as, space heating, air conditioning, hot water, industrial process heat, drying, distillation and desalination, and electrical power.

The level of outdoor temperature at which the heating capacity of a heat pump matches the heating requirements of a building.

The speed limitation imposed on an aircraft by aerodynamic overheating.

1. A combination of thermal cells.
2. A voltage source consisting of a number of bimetallic junctions connected to produce a voltage when heated by a flame.
3. A high-temperature, molten-salt primary battery in which the electrolyte is a solid, non-conducting inorganic salt at ambient temperatures.d

When power is required, an internal pyrotechnic heat source is ignited to melt the solid electrolyte which allows electricity to be generated electrochemically for periods from a few seconds to an hour.

This process is often used for military applications; such as, missiles, torpedoes, and space missions.

1. A method that teaches patients to increase or to decrease the temperature of their hands by feedback with signals indicating hand temperature.

This has been used primarily in the treatment of headaches.

2. The monitoring of skin temperature as an index of blood flow changes because of the dilation and constriction of blood vessels, the feedback being displayed to the patient on a video monitor, accompanied by an audible signal.

It is used for stress management and in the treatment of hypertension, migraine, and Raynaud disease (usually a bilateral disease of the blood vessels; especially, of the extremities which might be caused by cold or emotion, accompanied by intermittent pallor, cyanosis, and redness, and generally accompanied by pain).

A floating foam cover that insulates well, but it does not allow light to pass through.

It is often used in swimming pools and spas.

A material of low heat conductivity placed between materials of higher conductance to reduce the flow of heat; for example, certain metal framed windows are designed with thermal breaks to improve their overall thermal performance.

1. Tissue reaction to or injury, usually of the skin, caused by exposure to extreme heat.
2. A burn caused by excessive heat or a type of injury to the skin caused by heat, electricity, chemicals, light, radiation, or friction.

The amount of heat which can be retained by a thermal storage.

The time rate of heat flow through a body (per unit area) from one of its bounding surfaces to the other for a unit temperature difference between the two surfaces, under steady conditions.

The ability of a system to conduct heat, usually measured in units of thermal conductance.

Vegetation of sufficient abundance and height to significantly ameliorate weather effects; such as, wind, heat, cold, and snow.

A refining process in which gas oils are subject to extreme temperatures under severe pressure, so that the molecules are cracked and broken into new molecules.

The time period between the energization of a heat-producing device and the measurable effect of the heat produced.

A process for the reduction of complex organic materials (usually biomass waste products) into light crude oil.

The removal of salt from seawater by condensing purified vapor to yield a product in the form of distilled water.

The ratio of thermal conductivity to the heat capacity per unit volume for a material.

An important criterion for thermal insulators or conductors.

1. The study of the effects of thermal conditions on living organisms, either in a naturally heated environment or in one affected by human activities.
2. The study of the independent and interactive biotic and abiotic components of naturally heated environments.

1. A measure of the efficiency of converting a fuel to energy and useful work.
2. An expression of the effect of temperature on the rate of plant growth; assuming other condition are satisfactory.
3. The ratio of the amount of work performed by a heat engine in one cycle to the amount of thermal energy input required to operate the engine over one cycle; a measure of the efficiency of converting a fuel to energy and useful work.

The kinetic energy associated with the motion of atoms or molecules in a substance; such as, heat.

The storage of heat energy by means of sensible or latent heat technologies, in order to provide heating or cooling services at a later date.

The use of heat; for example, the injection of steam, to increase the amount of petroleum which can be recovered from a well.

A composite structure of building elements separating an interior temperature zone from the exterior zone.

1. A state in which all parts of a system are at the same temperature.
2. The condition under which two substances in physical contact with each other exchange no heat energy.

Fatigue in a material as the result of rapid increases to and/or decreases from operating temperatures, which can cause distortion or fracture.

An area over which therapeutic heating is most likely to be produced.

Acute peripheral pain which is reduced by multisensory interactions at the spinal and brain levels.

British scientists have discovered that people experience far less pain when they touch a sore part of their body with their hand; so, a gentle rub may very well help pain go away, or at least decrease.

• The researchers investigated what is called the "thermal grill illusion" or TGI, where participants placed their index and ring fingers in warm water and the middle finger in cold water.
• With the TGI, or thermal grill illusion, the brain perceives the cool water as painfully hot.
• The study looked at heat perception after participants submerged their fingers in water of different temperatures and pressed their fingertips together in different combinations.
• This allowed scientists to study the experience of pain without actually causing any injury to those who participated in the studies.
• The scientists involved concluded that touching an apparently painful part of the body will affect the way pain signals travel to the brain.
• While touch may help an individual to cope with pain to some degree, perhaps by easing very mild pain from a minor injury, it is unlikely to completely eliminate the experience of pain.
• Pain is a very subjective experience, and many factors, including psychological and emotional factors, affect the way it is experienced.

The ability of a material to store heat and to resist temperature changes, dependent on its density and specific heat.

A general term for any material or assemblage of materials used to provide resistance to heat flow.

A meteorological condition characterized by a temperature increase; rather than a decrease, with the altitude.

During a thermal inversion, air pollution can increase dramatically as a mass of cold air is held in place below a warmer mass of air.

The absence of air circulation prevents the pollution near the earth's surface from escaping.

Atoms with low ionization potentials can be ionized by contact with the heated surface of a metal, generally a filament, having a high work function (the energy required to remove an electron from its surface) in a process called thermal, or surface, ionization.

This can be a highly efficient method and has the experimental advantage of producing ions with a small energy spread characteristic of the filament temperature, typically a few tenths of an electron volt, as compared with beam energies of thousands of electron volts.

The filaments, generally made of platinum, rhenium, tungsten, or tantalum, are heated by current.

Surface ionization requires a nearby source of atoms, often another filament operating at lower temperatures.

Samples can also be loaded directly on the filament, a widely used and successful technique and one that has resulted in many interesting chemical treatments of the sample when it is deposited on the filament.

One such application changed lead from a difficult to an easy element to analyze, enabling important geochronological and environmental measurements.

A disadvantage of thermal ionization is the possible change in isotopic composition during the measurement. This effect is caused by Rayleigh distillation, wherein light isotopes evaporate faster than heavy ones.

Studies done on isotopes that come from radioactive decay; such as, those used in determining the ages of rocks, encounter this problem, but it is correctable using the measured values of the isotopes that are not radiogenic.

With few exceptions the use of a thermal source requires the chemical separation of the sample. Useful data are commonly obtained on extremely small (nanogram) samples.

The maximum amount of power which a transmission line can carry without suffering heat-related damage to line equipment, especially conductors.

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.

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.

The release of heated fluids into a body of water, that results in increased water temperature that is harmful to the environment.

An excessive raising or lowering of water or air temperatures above normal seasonal levels caused by industrial processes or other human activities.

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.

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.

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.

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.

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.