Why are we talking about Heat Stress?
Working in the heat is not just uncomfortable — it can be dangerous. When the body gets too hot and cannot cool down, it can lead to heat exhaustion or heat stroke. Heat stroke is a medical emergency and can kill.
Site work makes this worse. We often work in direct sun, wear PPE that traps heat, and do physical work that raises body temperature. On hot days, we all need to look out for ourselves and each other.
How to spot heat illness symptoms
Learn to recognise the early warning signs — in yourself and your workmates.
Heat exhaustion (early stage — can be treated):
Headache and dizziness
Feeling very tired or weak
Heavy sweating
Fast heartbeat
Feeling sick or being sick
Cramps in arms, legs or stomach
Pale, clammy skin
Heat stroke (medical emergency — call 999):
Confusion, slurred speech, or acting strangely
Hot skin that has stopped sweating
Very high body temperature
Fast breathing
Loss of consciousness or seizures
If you see signs of heat stroke, call 999 immediately. Move the person to a cool place and try to cool them down while you wait for help. Do not leave them alone.
Personal and environmental risk factors
Some people are at higher risk than others, and some conditions make heat stress more likely.
1. Personal risk factors
Health conditions: Heart, lung, or kidney problems, diabetes, or being overweight all increase risk.
Medication: Some medicines affect how your body handles heat. Check with your doctor if unsure.
Hydration levels: Starting the day already dehydrated (e.g. after alcohol the night before) makes heat stress much more likely.
Fitness and acclimatisation: Your body needs time to adjust to hot weather. Risk is higher in the first few days of a heatwave.
Age: Older workers and very young workers are more at risk.
2. Environmental risk factors
Direct sun and high temperatures
High humidity — sweat cannot evaporate, so the body cannot cool itself
Heavy physical work — generates more internal body heat
Working near hot equipment or in enclosed spaces (e.g. roof spaces, vans, plant rooms)
Wearing PPE or heavy clothing that traps heat
Using PPE safely in warm weather
PPE is still required in hot weather — do not remove it to cool down. Instead, use it correctly:
Breathable hi-vis: Where provided, use lightweight, breathable hi-vis instead of heavy jackets.
Head protection: Use sweatbands under hard hats and wide-brim hard hat covers where available to protect your neck and face from the sun.
Sun cream first: Apply sun cream before putting on PPE. Reapply during breaks on exposed skin (face, neck, arms).
Stay covered: Loose, lightweight, long-sleeved clothing under PPE protects against sunburn better than bare skin.
Never remove required PPE (e.g. eye or hearing protection) just because it feels hot — find a cooler way to work instead, such as more frequent breaks.
What to do when it's too hot
Speak up early. Tell your supervisor as soon as you feel unwell — do not wait until you feel very bad.
Stop and rest. Move to shade or a cool area immediately if you feel dizzy, sick, or overheated.
Buddy up. Check on your workmates, especially anyone doing heavy or isolated work.
Adjust the work. Where possible, heavy tasks should be moved to cooler parts of the day (early morning/late afternoon).
Increase breaks. Take more frequent, shorter breaks in the shade or a cool space.
Know when to stop. If temperatures or conditions become unsafe, work should pause. Always raise this with your supervisor.
How to keep cool
Drink water regularly — little and often, even if you don't feel thirsty. Don't wait until you're thirsty; by then you're already dehydrated.
Avoid alcohol, caffeine and sugary drinks — they can make dehydration worse.
Use shade for breaks and, where possible, for work areas.
Wear light-coloured, loose clothing where PPE requirements allow.
Pace yourself — slow down on physical tasks during the hottest part of the day.
Give your body time to adjust to hot weather, especially in the first few days of a heatwave.
Why this matters to you
Heat exhaustion can turn into heat stroke fast if ignored. What starts as feeling tired and dizzy can become a life-threatening emergency within a short time.
Dehydration affects concentration and coordination, increasing the risk of trips, falls, and mistakes with tools and machinery.
Existing health conditions get worse in the heat — extra strain on the heart and kidneys can be serious, even for otherwise healthy people.
Heat stroke can be fatal. Recognising the signs early and acting quickly protects you and your workmates.
Contact information for further info:
Callum Reid - callum@injoinery.com