News tagged with heat

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Hot cars can quickly prove deadly for kids

(HealthDay)—Before you decide it's safe to make a quick dash into the pharmacy while your toddler is asleep in a car seat during the hot months of summer, consider this: More than 600 children in the United ...

Aug 05, 2014
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Take 5: How to beat the heat

Your smartphone's weather app informs you of the impending heat wave and yet you refuse to skip your daily five-mile runs through downtown Boston. You've just spent the balance of the day studying at the ...

Jul 10, 2014
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Ways to avoid heat stroke

Having some fun in the sun is typically a popular summer activity, but it can also be dangerous.

Jun 24, 2014
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Heat waves reduce length of pregnancy

When temperatures reach 32°C or higher over a period of four to seven days, the risk of early-term delivery is 27% higher than on typical summer days, according to a study led by Nathalie Auger of the University ...

Apr 01, 2014
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Heat

In physics and thermodynamics, heat is the process of energy transfer from one body or system to another due to a difference in temperature. In thermodynamics, the quantity TdS is used as a representative measure of the (inexact) heat differential δQ, which is the absolute temperature of an object multiplied by the differential quantity of a system's entropy measured at the boundary of the object.

A related term is thermal energy, loosely defined as the energy of a body that increases with its temperature. Heat is also loosely referred to as thermal energy, although many definitions require this thermal energy to actually be in the process of movement between one body and another to be technically called heat (otherwise, many sources prefer to continue to refer to the static quantity as "thermal energy"). Heat is also known as "Energy".

Energy transfer by heat can occur between objects by radiation, conduction and convection. Temperature is used as a measure of the internal energy or enthalpy, that is the level of elementary motion giving rise to heat transfer. Energy can only be transferred by heat between objects - or areas within an object - with different temperatures (as given by the zeroth law of thermodynamics). This transfer happens spontaneously only in the direction of the colder body (as per the second law of thermodynamics). The transfer of energy by heat from one object to another object with an equal or higher temperature can happen only with the aid of a heat pump, which does work.

This text uses material from Wikipedia licensed under CC BY-SA