Heat Stress at Work: Prevention for Employers
India's hot season is long, and in many regions it is getting more intense. For workers on construction sites, in warehouses, at loading docks, in foundries and in commercial kitchens, heat stress at work is not an inconvenience. It can lead to dehydration, fainting, injuries from reduced concentration, and in severe cases heat stroke, which can be fatal.
The good news is that heat illness is largely preventable. This guide sets out the practical steps employers and supervisors can take.
How heat affects the body
The body cools itself mainly by sweating. When air temperature is high, humidity stops sweat from evaporating, or the work is physically heavy, the body can store heat faster than it can lose it. Heat-related illness then progresses along a spectrum:
| Condition | Common signs | What to do |
|---|---|---|
| Heat rash | Small red itchy bumps | Cool, dry skin; loose clothing |
| Heat cramps | Painful muscle spasms | Rest in shade, fluids with salts |
| Heat exhaustion | Heavy sweating, weakness, dizziness, headache, nausea | Stop work, shade, fluids, cool down, medical review |
| Heat stroke | Confusion, collapse, seizures, very high body temperature, skin may be hot | Emergency – call for help and cool immediately |
Heat stroke is a medical emergency. Any worker who becomes confused, slurs speech or collapses in the heat needs urgent help.
Who is most at risk of heat stress at work
Risk depends on the environment, the work and the person:
- Environment: high temperature, high humidity, direct sun, radiant heat from furnaces or ovens, little air movement
- Work: heavy manual effort, long shifts, protective clothing that traps heat
- Person: new joiners not yet acclimatised, people returning from leave, older workers, people with heart disease, diabetes or high blood pressure, and anyone who is unwell or dehydrated
Some medicines can affect how the body handles heat. Encourage workers on long-term medication to ask their doctor whether they need extra precautions.
Step 1: Assess the heat risk
Air temperature alone can mislead. Many occupational health programmes use the Wet Bulb Globe Temperature (WBGT), which combines temperature, humidity, sun and wind. If you cannot measure WBGT, use the heat index from weather services and local heat alerts. India Meteorological Department heatwave warnings and state or city heat action plans are useful triggers for stepping up controls.
Walk the site and map hot spots: roofs, metal sheds, kitchens, near furnaces, loading bays facing the afternoon sun.
Step 2: Put water, rest and shade in place
These three controls do most of the work:
- Water: Cool, clean drinking water within easy reach of every work area. Encourage small amounts often rather than large amounts occasionally. For long, sweaty shifts, oral rehydration solutions or electrolyte drinks may help; a doctor can advise.
- Rest: Scheduled breaks that get longer as heat rises. Breaks should be in a cooler place, not just a pause on the job.
- Shade: Shaded or cooled rest areas with seating and airflow. Even a temporary canopy with fans makes a difference.
Step 3: Plan the work around the heat
- Move heavy tasks to early morning or evening where possible
- Rotate workers between hot and cooler tasks
- Use mechanical aids to reduce manual effort
- Improve ventilation, add spot cooling, insulate hot surfaces and shield radiant heat sources
- Choose light-coloured, breathable clothing where safety rules allow
Step 4: Build acclimatisation into onboarding
New workers and those returning after a week or more away are at higher risk. A gradual build-up over the first one to two weeks, starting with shorter exposure and increasing day by day, lets the body adapt. Supervisors should know who is new and keep a closer eye on them.
Step 5: Train supervisors and workers
Short, practical briefings work better than long lectures. Cover:
- early signs of heat illness in yourself and others
- the buddy system – each worker watches a colleague
- the right to stop and rest without penalty when unwell
- what to do and who to call in an emergency
Use the language workers speak, and repeat the briefing at the start of the hot season and on heat-alert days.
Step 6: Prepare for emergencies
Every hot site needs a clear first-response plan:
- trained first aiders on each shift
- a cooling kit: water, towels, ice packs, a fan or shade
- a known route and phone numbers for ambulance and the nearest hospital
- clear instructions to cool first and transport fast for suspected heat stroke
Fold this into your wider occupational health and safety plan and review it after any incident.
Health checks and vulnerable workers
A periodic medical examination can identify workers who may need extra precautions, such as people with uncontrolled blood pressure or diabetes. Use this information sensitively and confidentially, focusing on adjustments rather than exclusion.
How MeWeSalus Care can help
MeWeSalus Care supports employers with onsite clinics, first-response support and ambulance coordination, along with health checks that help identify workers at higher risk. We can also run heat safety awareness sessions before the summer season. To plan for the hot months, get in touch.
Frequently Asked Questions
Is heat stress only a problem for outdoor workers?
No. Foundries, kitchens, laundries, boiler rooms, poorly ventilated warehouses and metal sheds can be hotter than outdoors. Any job that combines heat, humidity and physical effort can cause heat stress.
What should a supervisor do if a worker becomes confused in the heat?
Treat it as a possible heat stroke, which is a medical emergency. Call for emergency help, move the person to shade, cool them quickly with water and fanning, and do not give fluids if they are not fully alert.
Do people get used to working in heat?
Partly. The body can acclimatise over one to two weeks of gradually increasing exposure, but acclimatisation is lost after time away, and it never makes extreme heat safe.
This article is for general information only and is not medical, legal or financial advice. Please consult a qualified professional about your specific situation.