'IRAQ AND THE PERSIAN GULF' [‎277r] (556/862)

- T. .U i
PUBLIC HEALTH AND DISEASE 429
or among heavily laden soldiers on a route march. It is rarely serious,
but may be fatal if the patient has a diseased heart. Severe headache
and some mental confusion for a few hours is apt to follow recovery
from the faint.
Heat exhaustion is characterized by collapse, profuse perspiration,
low blood-pressure, nausea and vomiting, and often muscular cramps.
The rectal temperature generally reveals slight increase of body
temperature, ioo° to ioi° F.
In heat hyperpyrexia the heat-regulating centres of the body fail as
the result of undue strain. Sweating stops and when the body
temperature reaches 108° F. coma and convulsions ensue. The
mortality rate is high. Heat hyperpyrexia is more likely to occur when
the atmospheric humidity is high (pp. 173-5), and in the lower delta
in and near Basra than elsewhere. The obese, thick-necked, chronic
alcoholic is specially prone to heat hyperpyrexia.
In recent years much study has been devoted to the causes and
prevention of heat-stroke. Loss of body heat occurs mainly through
the sweat glands. Excessive sweating results in the loss not only of
water but also of a large quantity of salt, sodium chloride. This loss
of salt is an important factor in exaggerating the more serious effects
of heat. Army experiments in India showed that after a route march
of 9 miles in the hot weather, with a shade temperature of loq^ 0 F.
and a relative humidity of 47 per cent., the average loss of salt per
man was 6-8 grammes, and the loss of water between 6 and 8 pints.
To maintain efficiency in the hot weather in the tropics a salt intake of
about an ounce a day is desirable; about half that quantity is usually
available in the diet. Ten grains of salt in a pint of water is quite
palatable.
Morton (1944) describing experiences with British troops in Iraq
in recent years says that the slogan ‘Drink more Water, Eat more
Salt’ was posted in all dining halls at the beginning of the hot weather.
During the heat wave of July 1940, when the temperature was above
120° F. on more than 5 days, extra salt was added to the dietary, and
men were warned to avoid constipation. Working hours started
earlier and stopped at H'30 a.m. An ample supply of cool water to
which salt was added was available in all workshops and men were
encouraged to drink little and often. As a result of these measures
only two cases of heat exhaustion occurred, a great improvement on
the experience of 1930 during a very similar heat wave.
Recent work seems to show that heat exhaustion and heat hyper
pyrexia are due exclusively to overheating of the body and not to any