If the bodies involved in heat transfer are not interacting with other bodies, the amounts of heat given by a hot body and received by a cold body are equal in magnitude.

The specific heat of a substance (denoted by the letter $c$) is the amount of energy required to raise the temperature of one kilogram of substance by $1$ degree. It also shows how much energy is released from a substance if the temperature of one kilogram of substance is reduced by $1$ degrees.

The amount of heat $Q$ that must be given to a substance to raise its temperature by a certain number of degrees depends on the specific heat $c$ of the substance, the mass of the substance $m$ and the desired temperature change $\Delta t=t_2^{\circ }-t_1^{\circ }$:

Thus, in the heat exchange, the temperature of the substance will either rise or fall. If the temperature does not change, there is no heat exchange.