You should by now have grasped differences in prejunctional and postjunctional factors between a healthy person and one with asthma.
Many patients report that their airways react to mist and/or cold air.
No clue, I am in the cold!
This is indeed a difficult question. If breathing occurs via the nose one would expect that there would have been adequate air conditioning. So mouth breathers (e.g. during strenuous exercise) are more likely to report such symptoms. The water content of saturated air is very temperature dependent. Thus at 0 °C the water content of saturated air is only 10% of that saturated at 37 °C; room gas at 20 °C and 60% saturated with water contains 10 mg water per litre, as compared with 42 mg per litre for alveolar gas at 37 °C. Hence the lower airways, when confronted with cold air, must now add water to and at the same time warm the inhaled gas. Lower airways, particularly the large airways with their small surface area compared to that of the nose, are not equipped to adequately condition the inspired air. Mouth breathing occurs during exercise and challenge tests. Water loss from the airway wall will increase the osmotic pressure. This may activate the prejunctional cascade of events, especially in inflamed airways. Post-exertional rewarming may give rise to hyperemia of the bronchial microvasculature, and thereby contribute to airway narrowing.