Above all, for the cure and prevention of coughs and colds people must not be afraid of cold, fresh air. A good many seem to fear that any exposure to cold air while one has a cough may bring about pneumonia or some other serious complication. It must not be forgotten, however, that the pneumonia months in the year occur in the fall and the spring, October and November and March and April producing most deaths from the disease, and not December, January and February. The large city in this country which may be said to have the fewest deaths from pneumonia is Montreal, where the temperature during December and January is often almost continuously below zero for weeks at a time and where there is snow on the ground for three or four months in succession. The highest death rate from pneumonia is to be found in some of our southern cities which have rather mild winters and rather equable temperature,--that is, no considerable variation in the daily temperature range. Cold air is bracing and tonic for the lungs and enables them to resist the microbe of pneumonia, and it is now recognized {205} by physicians that personal immunity is a much more important factor in the prevention of the disease than anything else. Coughs and colds and bronchitis and pneumonia, the respiratory diseases generally, are much less frequent in very cold climates than in variable regions. Arctic explorers are but rarely troubled by them, even though they may be exposed to extremely low temperatures for months. Men subjected to blizzards at thirty and forty degrees below zero may have fingers and toes frozen but do not have respiratory affections. Some years ago, it was noted that one of these Arctic expeditions had spent nearly two years within the Arctic Circle without suffering from bronchial or throat disease and within a month after their return in the spring most of them had had colds. Nansen and his men actually returned from the Arctic regions where they had been in excellent health during two severe winters to be confined to their beds with grippy colds within a week of their restoration to civilization, with its warm comfortable homes and that absolute absence of chill which is connected in so many people's minds with the thought of coughs and colds.