Michael Patkin's

Winter croup and bedroom temperatures

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SIR: Each winter brings another epidemic of "croup" in young children, and more bronchitis to elderly patients and other susceptible groups. This misery to patients is a drudge to doctors and a heavy expense to the nation.

During three winters in Dungog, it has become obvious to us. as well as to many more serious students of this subject, that croup and bronchitis occur more frequently in cold weather (Bridges-Webb'). While this Is hardly news, it seems worth noting that symptoms are worst at night and in the early morning, after several consecutive cold days, and in less expensive houses made of weatherboard or fibro rather than brick. These are the circumstances when bedroom temperatures are low.

On eight occasions last winter, when one had to see such patients at home and was able to measure the temperature of their bedrooms, it was between 45 and 48° F. (7-9°C). In one weatherboard house, the bedroom temperatures on three successive mornings and evenings were 48, 56, 48, 59, 40 and 53° F. In the house where one first lived on coming to Dungog, one noticed the heavy cloud of exhaled moisture as one lay in bed early on a September morning.

It seemed a reasonable possibility that the cold air itself was the cause of symptoms, If not of the croup or bronchitis. Half-way through last winter. we began a policy of deliberate advice to patients about warming their bedrooms, with striking results.

For patients with bronchitis and the parents of croupy children, the advice given was to buy a reliable wall thermometer and note the bedroom temperature late at night and early in the morning. Local retailers cooperated by laying in a stock of inexpensive thermometers costing about $1 each for those who lacked them, When the temperature fell below 65° F, the room was to be heated with an electric radiator, throughout the night if necessary. If the room air became dry, a pan of hot water was placed in front of the radiator, or an electric kettle kept boiling for some minutes.

Of some dozens of patients, not a single one failed to benefit from this simple measure, though the amount of benefit varied in degree. The most striking case was that of a 78-year-old woman who had nocturnal asthma each winter for some years, her symptoms unrelieved by the usual gamut of treatment. Wheezing was quite abolished by this simple expedient. The parents of most children affected noticed an improvement not only in the patient, but also in other children sharing the bedroom, whose symptoms of night cough had not been sufficiently bad to warrant a medical consultation.

No complications were noted from this advice. Parents and patients were warned of the risk of a, fire, but the relatively safe design of modern radiators, such as the "Vulcan", made this a minor worry. Some comments were made about the cost of the extra electricity, and one house­hold found their television reception impaired. With elderly patients owning antiquated radiators there was some concern about safety, but the relatives were usually able to take charge of the situation. Raising the air temperature relieved winter respiratory symptoms in a manner uninfluenced by warm bedclothes and electric blankets.

Doubtless other factors besides air temperature cause croup and bronchitis. The prevalence of an adenovirus, crowding of susceptible people with decreased 'ventilation, general body cooling, individual susceptibilities, diseased tonsils and previously damaged respiratory tracts are all relevant. However, a study of epidemiology, as well as simple daily observation, suggest+s the possible role of cold air, Decades ago, Starling noted the slowing effect of lowering temperature on the movement of carbon particles by the ciliated lining of the trachea, and there should be similar effects on mucus accumulation and mucosal irritation.

Australia differs from colder countries, such as Canada and Russia, in that the impact of winter is not severe enough to warrant a complete cultural adaptation, reflected in double glazing, heavy clothing and continuous home heating. Britain is in this half-way position, though the climate of opinion is altering slowly there. Even tropical Africa has a problem of this kind, however unlikely it may seem at first. Schweitzer2 noted:

In the dry season the nights are fresher and colder than at other times, and as the Negroes have no bed clothes they get so cold in their huts that they cannot sleep, even though, according to European standards, the temperature is still fairly high. On cold nights the thermometer shows at least 68° F, but the damp of the atmosphere, which makes people sweat continually by day, makes them thereby so sensitive they shiver and freeze by night. White people, too, suffer continuously from chills and colds in the head . . . At the beginning of the dry season there is as much sneezing and coughing in the church at Lambarene as there is in England at a midnight service on New Year's Eve. Many children die of unrecognized pleurisy.

In the Highlands of New Guinea, a high incidence of bronchitis has been related to formaldehyde from wood fires in huts (Cleary and Blackburn3). Formaldehyde has been found to depress ciliary activity and mucus flow in animal experiments, but the type of classical observation made by Starling on the effect of cold temperatures may be more important in an Australian environment, and in other comparable countries.

The usefulness of 'warming bedroom air during the winter is suggested. rather than proven. It does, however, provide a practical measure that parents of croupy children and patients with bronchitis can try. Further observations of clinical impressions and temperature recordings are justified. Twenty-four hour thermography of bedrooms should be compared. with simultaneous out-of-door records over several days, to determine the effect of different building materials, and the cooling effect on houses of a cumulative series of cold days. There are important implications for builders, architects and heating engineers. Without doubt they already have data which are of medical importance, and an "interdisciplinary" approach is likely to give mutual interest and benefit. Schoolroom temperatures may also deserve study, or at least the purchase of an inexpensive thermometer; these rooms are large and exposed, and not warmed by cooking activities, night heating or a hot-water service.

The idea of studying bedroom temperatures in winter and correcting the cold is simple. Its medical implications would appear wider, and worth further study.

Michael Patkin, David Freeman
Dungog, N.S.W., 2420.          

 2 Schweitzer, A "On the Edge of the Primeval Forest", reprinted 1961, Fontana Books: 43.

3 Arch. environm. health, 1963, 17: 785 ; quoted in Med.. J. Aust., 1969, 1: 239.