Extra salt is needed during hot weather
In a tropical country like Papua New Guinea it is common to have an intake of the equivalent of
three grams of sodium chloride. People who move from a temperate to a hot climate may find that
their bodies' salt-retaining mechanisms undergo a short period of adjustment. The body has special
hormones to help retain sodium.
It is common for Australian adults to consume 8 to 12 grams of salt per day (about 160 to 240
millimoles sodium). The National Health and Medical Research Council (NH&MRC) of Australia
recommends that we have between 2 and 5 grams (40 and 100 millimoles) per day. Most
Australians should therefore reduce their salt intake. We should not require salt even as the
seasons change and the weather becomes hot.
There has been concern whether extra sodium might be required in extremely hot work
environments that lead to profuse sweating (and associated sodium loss), for example, the pot
room of an aluminium smelter. However, hormones in the body can regulate the amount of
sodium in sweat, causing it to fall as the rate of sweating increases. Special circumstances like this
probably deserve special consideration, but supplementary salt tablets will not necessarily be
required, even in extreme environmental circumstances.
We are concerned these days about the adverse effects of sodium on health, especially its effects
on the development of high blood pressure and osteoporosis. Most people are now aware that
many commonly consumed foods such as bread, butter, margarine, and tomato sauce contain
added sodium or salt, and have changed to reduced sodium varieties.