When Did You Last Hydrate?

UNDERSTANDING HYDRATION AND HEAT ILLNESS

The human body regulates temperature through sweating, but this also removes vital water and electrolytes:

• Workers can lose up to 600ml of sweat per hour, or 6 litres in a 10-hour day.
• Dehydration reduces blood volume, increases body temperature, and raises the risk of heat illness.
• Fatigue and reduced concentration from dehydration increase the chance of incidents and mistakes.

Remember: Even passing through a work area can put you at risk if you are dehydrated, stay alert and hydrated.

SIGNS OF DEHYDRATION AND HEAT STRESS

Look for:

• Dry mouth
• Muscle cramps or aches
• Headaches or nausea
• Dizziness, disorientation, or fainting

“80% of your brain is water – don’t let dehydration slow you down!”

IMPROVING HYDRATION

Simple strategies to stay safe and perform at your best:

• Drink regularly, even before feeling thirsty.
• Supplement with electrolytes during heavy sweating to
• Replace fluids and electrolytes efficiently
• Maintain energy and concentration
• Delay fatigue
• Keep water bottles visible and accessible at all times.
• Supervisors should monitor workers for early signs of dehydrationand heat illness.

KEY FACTS

• 80% of your brain is water
• 92% of blood is water
• 1% dehydration → thirst and decreased physical performance
• 10% decrease in mental performance when thirsty

QUICK QUIZ

1. What are the main risks of dehydration on site?
2. How much sweat can a manual worker lose in an hour?
3. Name at least three signs of heat stress or dehydration.
4. What strategies can you use to stay hydrated during a hot shift?

KEY TAKEAWAYS

• Hydration is critical for safety, health, and performance on site.
• Sweating leads to water and electrolyte loss, affecting focus, strength, and reaction times.
• Signs of dehydration include dizziness, cramps, headache, nausea, and disorientation.
• Plan hydration breaks and consider electrolyte supplementation during hot or physically demanding work.