Why heat stress is a workplace risk
Heat stress occurs when the combined burden of environmental heat, physical effort and clothing challenges the body’s ability to cool itself. In a humid setting such as Douala, sweat may evaporate less effectively. Heavy lifting, hot surfaces and restrictive protective equipment can increase the burden further.
The ILO identifies excessive heat as an important occupational hazard, including outside formally declared heatwaves. Employers should therefore plan for routine hot work, not wait for an exceptional weather alert. This guide applies to outdoor construction and port work as well as kitchens, workshops and poorly ventilated indoor areas.
Recognise heat exhaustion and heatstroke warning signs
Headache, dizziness, weakness, nausea, heavy sweating and unusual tiredness can indicate heat illness. Stop the activity, move the person to a cooler place, seek trained first-aid help and follow your site’s medical procedures. Symptoms can overlap with other conditions, so do not assume the cause without appropriate assessment.
Confusion, collapse, seizures or altered consciousness during hot work can indicate heatstroke, a medical emergency. Activate local emergency arrangements immediately and begin rapid cooling using your trained first-aid protocol while professional help is obtained. Do not wait for the person to stop sweating: sweating may still occur.
Never give oral fluids to someone who is confused, unconscious or unable to swallow safely. Do not leave an affected person alone or simply tell them to return to work once they feel slightly better.
Assess the task, not just the weather forecast
Consider air temperature, humidity, direct sun, radiant heat, airflow, work intensity, clothing and time spent exposed. A phone’s weather reading is not a complete assessment of conditions beside a hot process or on a sun-exposed deck.
Competent assessment may use wet-bulb globe temperature or another suitable method, interpreted alongside workload and clothing. There is no single universal safe temperature or work-rest schedule for every job. Do not copy a threshold from another country without checking its assumptions and local applicability.
New starters, workers returning after an absence and people with relevant health concerns may need additional arrangements. Use confidential occupational-health advice where appropriate rather than asking supervisors to make medical judgements.
Build heat controls into the work plan
Reduce heat at source where possible: provide shade, insulation from hot surfaces, suitable ventilation or mechanised handling. Move strenuous tasks to cooler periods when practicable, and avoid increasing other risks through poor lighting or unsafe shift changes.
Provide readily accessible drinking water, encourage regular drinking and arrange recovery breaks in a suitable cool or shaded area. Set the frequency through your heat assessment rather than a fixed rule for every worker. Gradually build up exposure for new or returning workers through a planned acclimatisation programme.
Use a buddy system, train supervisors to recognise changes in behaviour and make it clear that reporting symptoms will not be punished. Plan relief coverage so a person can stop safely. Never remove essential protective equipment as an informal solution to heat: change the work arrangements instead.
A practical example for a cargo-handling team
Before a demanding outdoor shift, a supervisor reviews the work and expected conditions with the team. Mechanical handling reduces heavy manual effort, shaded recovery space is available away from moving vehicles, and drinking water can be reached without crossing unsafe routes.
The team agrees how to call for help, who provides first aid and how an ambulance can reach the work area. The supervisor checks actual conditions and worker feedback throughout the shift, adjusts the plan when conditions change and records lessons for the next job. This is an illustrative example, not a report of a specific SQMI client.
Quick checklist
- Assess heat, humidity, workload and protective clothing together.
- Provide water and a safe, suitable recovery area close to the work.
- Plan acclimatisation and risk-based work-rest arrangements.
- Brief workers on symptoms, buddy checks and stop-work arrangements.
- Confirm first aid, rapid cooling arrangements and emergency access.
Common questions
- Can heat stress occur when there is no heatwave?
- Yes. Physical effort, humidity, hot processes and protective clothing can create significant heat exposure during normal working conditions.
- Is drinking water enough to prevent heat illness?
- No. Water is important, but workload reduction, cooling, recovery, acclimatisation and monitoring are also necessary according to the assessment.
- Does heatstroke always cause dry skin?
- No. A person with heatstroke may still sweat. Altered mental state, collapse or seizures during heat exposure require urgent emergency action.
- What temperature is safe for every workplace?
- There is no universal temperature suitable for every job. Assess environmental conditions, physical effort, clothing and individual needs using competent guidance.
Sources and further reading
This article is general guidance for awareness. Apply it through your own site-specific risk assessment and the laws and standards that apply where you work.