Scientifically
Formulated
Isotonic Liquid
Electrolyte

Prevention of dehydration
Ensuring that workers are adequately hydrated is one of the most effective interventions for managing the physiological strain associated with working in hot environments (Miller and Bates, 2010).

Physical work increases heat production in the body. An adequate level of hydration is essential to dissipate this heat, with the blood plasma acting both to transport heat to the body surface and as the source of the fluid lost in sweating. Failure to replace fluid losses reduces plasma volume and compromises the ability of the circulatory system to maintain sufficient blood flow simultaneously to the skin and the working muscles, which leads to muscle fatigue, increases in body temperature and ultimately excessive levels of physiological strain (Miller and Bates, 2010).

Maintaining sufficient levels of hydration is imperative for preventing excessive levels of physiological strain while working in heat. Unfortunately, many heat-exposed workers disregard recommendations for frequent fluid consumption and do not voluntarily drink enough water to replace the sweat loss in hot environments (Armstrong et al., 1985). Under such circumstances workers develop voluntary dehydration simply because they do not ingest sufficient fluid to offset their losses from sweating and urination. Thirst is an inadequate stimulus to drinking and this further contributes to the development of voluntary dehydration. It should be noted that the development of dehydration while working in heat may also be involuntary and the result of the non-availability of water in workplaces (Clapp et al., 2002).

The key to ensuring proper hydration levels while working in heat is to start work in a well-hydrated state and to maintain this, if necessary, with scheduled drinking. The more severe the thermal environment, the greater the potential benefits from improvements in the hydration status of workers.

The establishment of a culture of „hydration awareness‟ among mineworkers exposed to work in hot environments is an essential part of the effort to manage physiological strain. This may require changing of habitual behaviours in relation to the timing and quantity and type of fluid ingested, the objective being to start the work shift in a well-hydrated state and to maintain this by consuming fluid during the work shift.

Fluid consumption during the work shift cannot be left to voluntary drinking. Minimum fluid intakes must be prescribed and strategies put in place to ensure compliance and that water is available at the place of work. The current recommendation for the South African mining industry is that fluid replacement beverages (preferably only water or hypotonic fluids) be available at the place of work and that a fluid replacement regimen of at least 2 x 250 ml – 300 ml per hour be observed. The water should be cool (about 15°C), palatable and of good quality (potable) (Department of Mineral Resources, 2002).

Where sweating is exceptionally heavy or for prolonged physical work in heat there can be advantages to using electrolyte replacement beverages, which provide some carbohydrates as well (Clapp et al., 2002). The beverage chosen should be one that is formulated specifically for industrial use rather than products designed for sportsmen, which are frequently high in carbohydrate content because the maintenance of blood glucose levels during heavy exercise is a priority (Miller and Bates, 2010).

In an industrial setting where high volume consumption of fluid is a priority, the use of the latter products can lead to an excessive calorie intake and, considering that a large portion of the South African population is overweight, the additional calories in beverages can be detrimental, in the long run, to the health of some workers.