Toolbox Talk: Heat Stress – How to Recognise and Reduce the Risks

July 8, 2025

Heat Stress at WorkWhat is Heat Stress?

Heat stress occurs when the body struggles to regulate its internal temperature. It’s not just about high air temperature – factors like work rate, humidity, and clothing also contribute. If unmanaged, it can cause serious health issues or even death.

Common Symptoms of Heat Stress

Recognising the early signs is critical. Symptoms can vary from person to person, but typically include:

  • Inability to concentrate
  • Muscle cramps and heat rash
  • Excessive thirst
  • Fainting or dizziness
  • Headache, nausea, moist skin (heat exhaustion)
  • Hot, dry skin, confusion, loss of consciousness (heat stroke – a medical emergency)

Where and When Does Heat Stress Happen?

Heat stress is more likely when workers are:

  • Wearing heavy PPE or non-breathable clothing
  • Doing physically demanding tasks
  • Working in high humidity or near heat sources
  • Unable to take breaks or hydrate regularly
  • Working outdoors in full sun (e.g. riverside, mountain climbs)

How to Assess Heat Stress Risks at Work

You should assess:

  • Work rate – higher effort = more body heat
  • Working environment – temperature, humidity, air movement
  • PPE or clothing – can restrict heat loss
  • Individual factors – age, health conditions, medication

At Call of the Wild we encourage open communication with our instructors and we encourage you to do the same with your Line Manager. If you feel symptoms coming on, let us know early.

How to Prevent or Reduce Heat Stress

Schedule Smart:

  1. Plan tasks during cooler parts of the day
    1. Use shaded rest areas
  2. Stay Hydrated:
    1. Sip cool water regularly — before, during, and after activities
    2. Don’t wait until you’re thirsty
  3. Adapt PPE (Safely):
    1. Use breathable or cooling clothing if available
    2. Allow PPE removal during breaks where safe to do so
  4. Monitor Vulnerable Individuals:
    1. Those with health conditions, on medication, or inexperienced workers may be more at risk

We can provide individual risk assessments if needed

Working in the Sun

Excessive sun exposure can cause:

  • Sunburn or blistering
  • Premature skin ageing
  • Increased risk of skin cancer

Encourage sun protection: use sunscreen, take shaded breaks, wear UV-rated PPE where possible.

What the Law Says

Under the Workplace (Health, Safety and Welfare) Regulations, employers must:

  • Ensure a reasonable indoor temperature
  • Provide outdoor protection from adverse weather
  • The Management of Health and Safety at Work Regulations require employers to:
  • Assess heat-related risks
  • Implement appropriate controls

Note: There’s no legal maximum workplace temperature, but heat is considered a hazard and must be managed like any other.

If you’re struggling with heat or worried about heat stress, please speak to your Call of the Wild Instructor or your Line Manager. It’s better to have a plan in place than to manage a crisis on the mountain.

Related

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