The Gisborne Times. PUBLISHED EVERY MORNING. THURSDAY, FEBRUARY 18, 1909. HEAT AND HEALTH.

Gisborne Times, Volume XXVII, Issue 2429, 18 February 1909, Page 4

The Gisborne Times. PUBLISHED EVERY MORNING. THURSDAY, FEBRUARY 18, 1909. HEAT AND HEALTH.

Whilst the weather reports receive considerable attention from the average person there are few who take much heed of the records of the “wetbulb” thermometer. After a hot day most people are anxious to know what temperature has been recorded, and tho dry bulb reading is freely quoted. And yet, the wet bulb reading is much the more important from a health point of view. It is the evaporation of moisture from the skin that enables a man to exert himself freely even in hot climates. The healthy body maintains a wonderfully even temperature, and it does so because with an increase of heat the body pea-spires and the consequent evaporation uses up a great deal of the surplus heat-. The wet bulb thermometer is important simply because it shows whether the evaporation of the perspiration may proceed quickly or not. The instrument is, of course, a thermometer with the bulb swathed in a pieco of wot muslin. If the air is dry the moisture evaporates readily, absorbing heat from the thermometer and the mercury falls. If the air is very moist there is little or no evaporation and consequently the wetbulb and dry bulb readings are nearly tho same. AVith tho dry bulb reading at 100 deg. Fall., the wet bulb reading may be very low. On a muggy day, on the other hand, although the dry bulb reading may be low and the wet bulb reading comparatively high tho weather is oppressive because the air is moist. The human body resembles a wet bulb thermometer because its surface is moist, and atmospheric conditions causing a high wet bulb reading cause, also, an accumulation of beat in the body that may be fatal. Indeed if the wet bulb reading is as high as SBdeg. Fall., the surplus heat cannot escape from the body and the bodily temperature will rise until death occurs. The enervating day is not the hot sunny day but tlie close moist day. AY hen the wet bulb reading is high, therefore, exertion should be avoided by both man and beast. AA r ith these- facts in mind it is easy to understand how it was that during tho week which preceded the recent wet weather tho atmosphere was distinctly oppressive, although the maximum reading of the thermometer rarely reached 80 degrees. There was at that time a good deal of -humidity in the atmosphere and the average readings of the wet bulo from February 4th to February 10th varied from 63 degrees to as high as 71. Therefore, the cool spell which accompanied tho blustering Southerly came as a welcome change to all of us. Under tho circumstances it will be wise in future to pay more attention than formerly to t-lic wet bulb record in the weather report.