6. Dehydration
When working in very hot conditions, dehydration can seriously affect a worker’s health and their ability to function safely.
How to reduce the effects of dehydration
- Encourage workers to frequently drink cool water (rather than tea, coffee or carbonated drinks)
- It is better to drink in small amounts to compensate for the effects of sweating
- Do not rely on workers saying they are thirsty. It is not a good indicator of dehydration, more an early sign that they are starting to suffer from its effects
- When working at a high rate in heat stress[8] conditions, workers should drink around 250 ml (half a pint) every 15 minutes
- If you have workers exposed to heat stress conditions, encourage them to be adequately hydrated before they come to work
Where ability to drink is restricted
Some situations make it harder for workers to drink, for example if they are wearing personal protective equipment (PPE)[9].
In these situations you could encourage workers to drink:
- 500 ml (a pint) of water per hour before work starts
- the same amount during their rest periods
If water loss is significantly greater through increased sweating, then they should increase the amount they drink proportionately.
Even if workers replenish lost sweat with equal amounts of water, they may still be dehydrated due to lost salt from the body. It is therefore a good idea to have drinks that contain the salts needed.