When the body emits radiation, the temperature of the body will decrease. This phenomenon is known as radiative cooling.
All objects with a temperature above absolute zero (-273.15 degrees Celsius or -459.67 degrees Fahrenheit) emit thermal radiation in the form of electromagnetic waves. The intensity and spectrum of this radiation depend on the temperature of the object. According to Stefan-Boltzmann's law, the rate at which an object radiates energy is directly proportional to the fourth power of its temperature.
When the body emits radiation, it is losing energy in the form of heat. This energy loss causes the body's temperature to decrease over time. It is the same principle that allows objects to cool down by radiating heat into the surrounding environment.
It's worth noting that the rate of temperature decrease due to radiative cooling can be influenced by various factors, such as the temperature of the surroundings, the emissivity of the body's surface, and other forms of heat transfer (conduction and convection). However, in general, when an object emits radiation, its temperature will decrease.