When two bodies at different temperatures are placed in thermal contact with each other, heat flows from the body at a higher temperature until they both acquire the same temperature. Assuming that there is no loss of heat to the surroundings, then:

Hint: In this question, we will discuss the basics of heat and then take an example to explain and get the required answer. Further, we will discuss the basics of temperature. We will also study the thermometer and its types, for our better understanding.

Complete answer:
As we know that, heat is defined as a form of energy that gets transferred from one medium or object to another medium or object. If we take an example: when a cold body and a hot body is brought in contact with each other, here, the heat gets transferred from the hot body to the cold body until both the system of hot and cold attains equilibrium.
Also, when we take two bodies at different temperatures and place them in thermal contact with each other, then heat flows from the body at a higher temperature until they both acquire the same temperature i.e., reaches equilibrium. Here, if we assume that there is no loss of heat to the surroundings, then the heat lost by the hot body will be equal to the heat gained by the cold body.
There, we get the required result i.e., the heat lost by the hot body will be equal to the heat gained by the cold body.

Additional information:
As we know that the temperature is defined as the quantity measured by any thermometer. Also, here temperature is related to the average kinetic energy of atoms and molecules in a given system. When we know about the term absolute zero, it is the temperature at which there is no molecular motion in the given system. Further, we know that there are three main temperature scales that are: Celsius, Fahrenheit, and Kelvin.
Thermometer is a device that measures temperature or temperature gradient. A thermometer has two important elements that are:
A temperature sensor- bulb of mercury-in-glass thermometer acts as a temperature sensor; in this some changes occur with a change in temperature.
Some means of converting this change into a numerical this change into a numerical value.
A clinical thermometer is a small medical thermometer with a short but finely calibrated range. These are used by doctors in clinics. A clinical mercury thermometer has mercury in them which expands with the temperature.
The alcohol thermometer is also known as spirit thermometer. It is an alternative to the mercury-in-glass thermometer and has the same functions.

Note:
We can get the answer to this question by the 0th law of thermodynamics, according to this law heat transfers from hot body to cold body. We should remember that there are different types of thermometer present for different purposes, like- clinical thermometer; laboratory thermometer etc. thermometers have different limits. The S.I unit of temperature is Kelvin (K), 1K=-273.15 degree Celsius.