The relationship between heat and temperature

Do you know the difference between heat and temperature? Often these two concepts are confused with each other, being used in a wrong way. While they are closely related, they are not identical. Thus, while heat is a form of energy, heat energy, temperature is the quality that determines the direction of heat flow.

But What characteristics does each have? We are going to talk about this and much more in this special article. 

What exactly is heat?

During sunny days, and especially in summer, the expression we most often say is: "how hot!", Right? Well, this sensation is produced by the sun, which is an object much larger than planet Earth (it has a diameter of 696.000km, while our home 'only' measures 6.371km), and much hotter: about 5600ºC, compared to the 14ºC average recorded here.

The heat could be said to be a energy transfer from an object of higher temperature to another that is more 'cold'. Thus, between the two objects a thermal equilibrium would be reached, which is what happens, for example, when we get into bed in winter: the sheets and blankets are cold at first, but little by little they get warmer.

Heat energy can be transferred in three different ways:

• Radiation: when it propagates in the form of electromagnetic waves, such as solar energy.
• Driving: when it spreads by direct contact, such as when we put a spoon in fresh coffee.
• Convection: when it is propagated by means of a liquid or gas, like the heaters we have at home.

And, once done, the object can go to a different state, which can be solid, liquid or gaseous. These changes are known by the name of phase changes, which continually design Earth's nature. The most frequent phase changes in meteorology are:

• From solid to liquid, called fusion.
• From liquid to solid, called solidification.
• From liquid to gaseous, called vaporization.
• From gaseous to liquid, called condensation.

Heat energy is measured in Calories, unlike the temperature that is measured in degrees (either Kelvin, Celsius or Fahrenheit), or also in Joules (1 July is equivalent to 0,23 calories approximately).

Definition of temperature

The temperature is a property of matter that is measured by a thermometer. The closer one object is to another, the hotter it is, the higher its temperature. We ourselves, when for example we are sick and have a fever, our body temperature also increases.

There are three scales that measure it, as we have mentioned before:

• Celsius: the one we know and use the most in Europe, whose reference points are freezing (0ºC) and boiling (100ºC).
• Fahrenheit: it is used especially in Anglo-Saxon countries. Its reference points are the freezing of an antifreeze mixture of water and salt, and the temperature of the human body. 1ºC equals 33,8ºF.
• Kelvin: for scientific use. Its reference points are absolute zero and the triple point of water. 1ºC is equivalent to 274,15ºK.

Temperatures on Earth 

The temperature varies according to the altitude, with the proximity or distance of the sea and the equator, with the orography and also by the flora itself (The more wooded area there is, these plants generate water vapor when they photosynthesize, which can help us better cope with the heat). Broadly speaking, there are three major areas on the planet:

• Warm or tropical zone: located between the two tropics and divided by the equator into two equal zones. The average temperature is above 18ºC.
• Temperate zone (north and south): they extend from the tropics to the poles. The annual average temperatures remain around 15ºC. In regions located in the temperate zone, the seasons of the year are well defined.
• Cold zone (the poles): located between the Arctic Circle and the North Pole, and the Antarctic Polar Circle and the South Pole. Temperatures are practically always kept below 0ºC, even reaching -89ºC.

And the thermal sensation? 

Although in our area the thermometer marks a certain temperature, perhaps our body feels something different, which will then be the time to talk about the thermal sensation. What exactly?

The wind chill is the body's reaction to the time spent in an environment, and the sensation of heat is when it exceeds 26ºC, although it varies greatly depending on the season in which we are and on the person himself. For this reason, those who live in temperate or cold climates do not tend to like the humid heat of the Mediterranean very much, and those who live in tropical or subtropical climates often find it difficult to adapt to a cold climate.

And it is that the more humidity there is in the environment, the more heat it will feel; and the lower it is, the colder it will be. So, for example a temperature of 30ºC with 90% humidity, it will feel as if the thermometer is really marking 40ºC.

Did you know the relationship between heat and temperature?