It is believed that by thermometers (thermometers) we measure the Temperature. But I say that this is not true. Let's look at how the device works and what the principle of the thermometer is. Thermometers (thermometers) can be both electronic and mechanical. But what do thermometers actually measure? Such a thing as temperature in the real world does not exist. It was invented by physicists. Heat is yes, the temperature is not. This people came up with a measure of heat and called it temperature. For the first time this idea came to the pharmacist, who mixed drugs. He established the following gradation of heat: a cold body, warm, warmer and hotter. Of course, he defined all this, based on his feelings of warmth. So what actually measures the thermometer. The first thermometers were made of hair, usually horse. He was twisted into a spiral, and a small arrow was glued to the tip. Then a scale was applied. When the hair was heated, as, indeed, all the bodies, increased and gradually unwound, the arrow shifted and pointed to a new division on the scale. It is not difficult to guess that the device actually shows how the body size changes with heating. Thus, liquid thermometers act. Mercury or colored (usually red) alcohol, which fills the thermometer, from the heat expands and naturally the column of liquid increases in size. Electronic thermometers are based on the property of a thermocouple, changing their electrical properties from heat. A thermocouple is a pair of different conductors connected at the end. When heated or cooled, the EMF generated by them changes, which causes the arrow to move. The thermocouple, like most devices, is reversible - if we pass current through it in a certain direction, it will be heated or cooled. This method is used in the manufacture of Peltier elements.
The thermometer actually measures the size of the body. The size depends on the effect of heat. It means indirectly it shows us heating or cooling. We call it temperature. And there is a real unit of measurement.
Most likely such concept as temperature will disappear from our life. Remains only for calculations or scientific measurements. Why do we need to know what the temperature is outside the window. To choose the right clothes. Electronics is developing at a rapid pace. Perhaps the appearance of a device that will show us the picture, with what clothes we should wear, for example, a shirt and a windbreaker - this will be enough to feel comfortable on the street. For such devices the future.
P.S. The foto is taken from here and for the most curious the normal temperature of the cat is 38-39 degrees