Heat and Excessive Exercise at Work

Having to work in the heat is a reality for lots of people and dehydration can be become a major problem – whether you’re working inside or outside – if you are not drinking enough fluids.

Everyone needs to drink more to stay hydrated when out and about in the heat – but when you’re working or exercising for long periods in hot or warm conditions it can put extra stress on your body, particularly if you have to wear heavy or protective clothing.

Staying hydrated at work and watching out for the signs of dehydration is important. Mild dehydration can quickly worsen and lead to more serious problems such as heat stress or heat stroke if not dealt with at the right time.
The signs and symptoms of mild to moderate dehydration to watch out for include:

  • Sticky mouth or dry mouth
  • Increased thirst
  • Lethargy
  • Decreased urine output
  • Dark yellow urine


Heat strain, heat stress and dehydration

Working in hot environments raises your body temperature – firstly, from the accumulation of the surrounding heat (for example, heat generated by the sun, bushfires, machinery or equipment) and secondly, because the body generates its own internal heat when being physically active.

A healthy body functions best when its internal (core) temperature is kept at about 37°C. If we get too hot we start sweating – which helps cool us down as it evaporates. When we’re working hard in hot conditions the body has to work harder to cool down and we can lose as much as 2-3 litres of water every hour through sweating.

If we don’t drink enough to replace this lost water we can become dehydrated – and when we’re dehydrated we can’t sweat as much and we can’t cool down as fast as we need to.

When sweating is not enough to stop your body temperature rising and your body is not able to cool down, problems such as heat stress and other heat-related illnesses can start to occur. Dehydration and heat stress can also affect how you work – affecting things such as thinking and reaction times or make you feel more tired which can also increase the risk of work-related accidents.


Are you more at risk of dehydration?

Working in some types of industries or doing certain jobs may mean you have a higher risk of becoming dehydrated.

Factors that can contribute to dehydration include:

Being physically active at work

  • Doing manual work or strenuous, prolonged exercise (inside or outside) particularly in hot conditions when you’re likely to sweat more

Hot environments

  • Working outdoors in the heat ­– particularly if it’s humid (high humidity makes sweating less effective at cooling the body down)
  • Working in hot or poorly ventilated indoor environments such as heated gyms or hot warehouses
  • Working where heat can radiate from the ground (for example from roads, car parks or runways), accumulates in buildings (in places such as roofs, warehouses or factories) or be generated while working (such as cooking, heat lamps, spot lighting or machinery)
  • Working in heat while wearing heavy, dark coloured or protective clothing/uniforms can increase sweating rates

Spending long periods of time without access to water

  • If there are limited or no access to water or other drinks where you are working
  • Wearing protective clothing can make you feel the heat more and consequently sweat more – plus wearing full or half face masks makes drinking more difficult!
  • Being busy and forgetting to drink


Take time to rehydrate when working in the heat

Don’t wait until you feel thirsty; it’s better to have frequent, smaller drinks rather than large infrequent ones. Try to drink at least a small cup (200ml) of cool fluids every 15 to 20 minutes when it’s hot.

  • Try to make sure your drink is cooled (cool but not extremely cold to avoid stomach cramps)
  • Put it where you can easily (and safely) access it
  • Make sure your drink is close to where you are doing any hot or strenuous work

Using Hydralyte, specifically formulated to help to replace lost water and electrolytes, is a simple way to help you stay hydrated while working in the heat.