Why does hot weather cause problems for people with respiratory disease e.g. emphysema?
With an increase in temperature the humidity can change. If the air is too humid or not humid enough, it makes it more difficult to breathe. Heat causes things to expand — not just outside, but inside the body, as well — this can cause a narrowing of the bronchi leading into the lungs. The quality of the air often declines as temperatures increase. More pollen and allergens can be present in the air, as well as increased amounts of chemicals from vehicles — these can also increase the difficulty of breathing.
