There are a lot of stubborn myths about salt. For years we have had the idea that we need plenty of it in our diets, and in particular, that we should take salt tablets in hot climates. There is a grain of truth in this. Salt is sodium chloride; when we sweat we do excrete salt, and lose sodium; excessive sodium loss, if not replaced, could produce muscle cramps and dehydration. But this is a rare danger, to bodies unused to hot climates and exposed to bursts of heat. Acclimatization takes about a month.