Why is it cold when we breathe out smoke?

To explain this phenomenon, first try a small experiment like this: put salt continuously into a glass of water and stir well.

Photo: cbc.ca

Initially, the amount of new salt put into the cup will dissolve; until the amount of salt is removed even though it is stirred and strong, the amount of salt will not dissolve. This phenomenon is called saturation.

Air and water have the same characteristics. The amount of water vapor that air can tolerate has a certain degree.

But the ability of cold air to tolerate steam is much lower than hot air, so in the cold winter, the air vapor in the air by humans and exhaled animals will not be absorbed by outside air collecting more; This series of steams that catch cold will condense into tiny droplets and turn into white mist.