Heat waves pose a real and direct risk to people, especially workers who spend long hours outdoors such as those building or farming. International experts have noted in their latest report that heat is a growing problem in many regions, and high temperatures will become a regular part of workers’ daily lives. With this in mind, unions emphasise that all businesses should implement an occupational risk prevention plan. Workers must stop work when imminent danger is detected, and regular breaks and hydration are essential.
At what temperature is it dangerous to work?
There is no single temperature that automatically stops a job because a risk is present. No magic number exists. Instead, several factors influence danger, including the overall workload, fitness, medical conditions like diabetes, and clothing, among others, according to Antonia Fuentes, the safety lead for UGT Catalonia.
Companies should carry out an assessment plan to define maximum operating temperatures for each environment, adjusting for outdoor or indoor conditions. An office is not the same as a workshop with metalwork. This assessment, often described as thermal stress, comes with practical guidance from bodies like Emet when heatstroke, cramps, or sunstroke is possible.
Risk indicators for overheating consider humidity and thermal sensation. In a dry setting at 45% humidity, a worker should take extreme measures around 33 degrees, and at 41 degrees danger is clear. In Barcelona, with higher typical humidity around 60%, the necessary measures begin a few degrees earlier, around 30 degrees rising to 34 degrees where risk becomes evident.
What to do in an emergency?
If a worker feels fatigue, experiences a headache, dizziness, or muscle cramps, operations should pause automatically. These are common signs of heat-related illness. Heat stroke occurs when core body temperature climbs above 40 degrees. In such cases, the employee must stop work and notify a colleague so emergency services or medical help can be called.
If a heatstroke victim can reach a shaded area unaided, they should wait there for help. If not, a partner should assist. A worker has the right to halt activities if continuing would threaten health and should not be punished for doing so. In the event of unsafe conditions, a complaint can be filed with labor inspectors.
How often should breaks be taken?
Regular breaks, tailored to the type of work, are crucial for preventing heat-related accidents. The head of occupational health for UGT Catalonia notes that the break schedule should be defined in the risk assessment plan. Higher workloads require more frequent rests. Supervisors must ensure breaks are taken and that workers have access to cool or shaded areas for cooling down.
And how often do you need to moisturize?
Hydration plays a key role in preventing heat stress. Workers should drink fluids regularly, and isotonic drinks are recommended in hot conditions. The employer should cover the cost of these beverages as part of workplace health initiatives.
Which work clothes are suitable?
Shifts should be performed in light, breathable clothing that is appropriate for the task and approved by the employer. Protective sunglasses for those near furnaces or foundries, sun-protective clothing, and hats to reduce heat exposure may be necessary. Each sector may require different gear, but the employer must provide and maintain proper attire.
Exposure of large areas of the body is strongly discouraged by occupational health experts. Regardless of heat, removing a shirt is not advised for construction workers, gardeners, or seasonal staff since it raises burn risk. The guideline is to wear loose, cool clothing that still covers as much skin as possible.
How should the day be organized?
Rescheduling the day to reduce hours spent outdoors is a common union request to limit heat exposure. This is not automatically mandatory; it depends on agreements within collective bargaining. Employers retain flexibility in day planning, provided basic job security standards are met. Avoiding the hottest midday hours is recommended, though not compulsory.