Question

Why when exhaling in the morning or in cold weather, our breath looks like smoke? explain the respiratory mechanism that occurs with respect to it?

Answer 1

Well it has few things to do with biology,it can answered with the help of physics.

During winter the weather outside your body is pretty cold,but your hypothalamus has thankfully maintained an optimum temperture,so the air in your lungs is also lying at that temparature,which is high enough.

So,as soon as you breathe them out,they come in contact with air of cold temperature outside,take the latent heat for condensation and get condensed to small water vapours,and now the cloudiness appears due to their appreciable diameter than air particles.

Answer 2

The water vapor in the warm air that you breathe out will lose kinetic energy and condense into liquid water droplets, or even ice crystals, which we see as a cloud or fog.

Explanation:

In cold weather, your breath looks like smoke due to condensation of water vapor in your breath. The temperature in your lungs is around `37^@"C"` `(98.6^@"F")`, which is normal body temperature. Along with nitrogen, oxygen, and carbon dioxide gases, your breath also contains water vapor. If the temperature outside the body is cold, say `0^@"C"` `(32^@"F")`, the water vapor in the warm air that you breathe out will lose kinetic energy and condense into liquid water droplets, or even ice crystals, which we see as a cloud or fog.