Question: What is the difference between breathing cold air, room temperature air and hot air?

Helen Hanstock answered on 14 Nov 2016:

Cold air is a bit more of a stress on the airways because our body has to warm it which draws heat away from the airways themselves. Cold air also holds less moisture so dries out the airways too as the airway lining is used to humidify the air. In some winter sports endurance athletes doing really long and heavy training over several years this repeated drying of the airway can cause some inflammation and lead to mild exercise induced asthma in the cold. However it has been shown that the airways are quick to recover once skiers stop training so hard, so the damage is reversible.