Diseases, Conditions, Syndromes

High temps may up admissions, deaths in end-stage renal disease

(HealthDay)—For patients with end-stage renal disease (ESRD), extreme heat events (EHEs) are associated with increased risk of hospital admission and mortality, according to a study published online Aug. 9 in JAMA Network ...

Medications

Finding non-opioid alternatives for cancer pain

Westey Watson spent 18 years finishing concrete, then another 19 as a contractor—all the while beating up his body to the point of endless pain. To cope, he got in the habit of taking hydrocodone, or Norco, at 10 a.m. and ...

Cardiology

Protect your heart in the heat

With much of the nation facing a heat advisory this weekend, the American Heart Association, the world's leading nonprofit organization focused on heart and brain health for all, is urging people to take precautions to protect ...

Health

A better way to treat hypothermia

Although most of the western hemisphere is sweating in the summer heat, a team of U of M researchers are keeping cool by finding more efficient ways to tackle hypothermia.

page 1 from 23

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