Working in hot and cold environments

The annual occupational health and safety action plan (työsuojelun toimintasuunnitelma) must include measures for improving the workplace’s thermal environment.  

The thermal environment and its effects on workers’ health must be assessed by the occupational health service in the following: 

• occupational health service workplace survey report 
• pre-employment health examinations 
• other periodic health examinations carried out by the occupational health service. 

The occupational health service also issues recommendations for breaks, protective clothing, and preventing harm. 

Temperature limits and recommendations

The thermal environment must be suitable for human comfort and body temperature regulation. In addition to ambient temperature, the thermal environment includes air humidity, air movements (draughts), and thermal radiation. The thermal comfort of workers is affected by their clothing and the nature of their work (workloads and working methods). 

Guidelines for temperatures and air movement based on workload: 

• light seated work, 21–25 °C (e.g. cashiers, office workers) 
• light general work, 19–23 °C (e.g. shelving and picking small items) 
• moderate general work, 17–21 °C (e.g. warehouse workers, shop assistants) 
• heavy work, 12–17 °C (e.g. manual lifting of heavy objects). 

The recommended range for air humidity is 30–70 per cent. 

Working in hot weather and hot environments 

In the summer, many service sector workers suffer from hot working conditions. Shops, offices, and warehouses often have no air conditioning, or it is ineffective. In restaurants and kitchens, heat is a problem all year round, and ambient temperatures can reach over 40 °C. 

Working in a hot environment stresses the body. Our hearts must beat faster, eventually tiring. Typical symptoms of overheating include fatigue, headaches, and nausea. 

Workers can reduce their heat stress by wearing light and airy clothing suitable for their work. It is also important to maintain hydration and salt balance. Dehydration increases the temperature of our internal organs and further stresses our circulatory system. If protective measures are not taken, excessive heat can lead to muscle spasms, fainting, or even heatstroke. Heat impairs our thinking and increases the risk of accidents. 

Ways to beat the heat 

Fans can provide temporary relief during a brief heatwave, for example. Their positioning must be planned carefully to avoid draughts and the resulting health risks.  

If heat is a constant issue, more sustainable solutions are required. The most effective method is mechanical ventilation that includes air conditioning (introducing cold air into the workplace).  

Insulating heat sources can also reduce workplace temperatures considerably. 

Hot environments require more breaks 

If the workplace’s ambient temperatures cannot be reduced below 28 °C, workers must be allowed extra breaks. 

The recommendation is to rest for 10–15 minutes per hour of work. 

• If the ambient temperature remains below 33 °C, work 50 minutes and rest 10 minutes. 
• If the ambient temperature exceeds 33 °C, work 45 minutes and rest 15 minutes. 

Heavy manual labour requires special protective measures if ambient temperatures exceed 33 °C. These include examining the workers’ vulnerability to heat illnesses, using special protective clothing, and frequent breaks. Obviously, the primary solution should be appropriate ventilation and heat source insulation by technical means. 

Cold environments 

The service sector includes many cold workplaces, both indoors and outdoors. Outdoor work is required in warehouses, property maintenance, and ski resorts, for example. Indoor work may involve stocking freezers, working in milk storage rooms or cold stores, and processing meat in refrigerated facilities. 

Whether indoors or outdoors, cold work requires workers to transition between warm and cold spaces, which is particularly stressful for humans. 

Cold-related symptoms typically start when the ambient temperature drops below 10 °C. Cold temperatures are known to weaken the performance of our respiratory, circulatory, and musculoskeletal systems, which increases the stressfulness of work. Minor and moderate chilling may reduce manual dexterity while severe chilling reduces our capacity to function at all.  

Workers who regularly work in the cold for years develop more joint and muscle issues than workers who only work in warm environments. 

Ways to beat the cold 

Draughts are a common issue for cashiers and especially warehouse and office workers. Employers must provide appropriate clothing for these types of jobs: it must protect against draughts while being easy to put on and take off. 

Clothing is often the only way workers can protect themselves. In addition, adding thermal insulation to tools and machinery can sometimes be useful, for example. Draughts can be excluded by using dividers and screens or avoided by adding a fan heater for the workstation. Heaters are a fire risk and require special fire safety measures. 

Additional breaks protect against cold 

Chilling can be prevented by reducing the time workers are exposed to cold: 50 minutes of cold work followed by 10 minutes of other work, for example. Different work arrangements can be made to reduce the amount of time workers need to spend working in cold environments. Warm spaces must be available for any waiting periods, and a drying room must be available for wet clothing. 

Rules about cold work in collective agreements 

The collective agreements made by PAM do not include rules about excessive heat in the workplace, but supplementary pay for cold work is included in many agreements. 

Commercial sector’s collective agreement 

Warehouse workers are paid an environmental supplement of 7–11 per cent for working in outdoor or unheated warehouses in wintertime, for example. The supplement for hours worked in frozen food stores is 20 per cent. 

Cashiers and shop assistants are paid a cold store supplement, minimum five per cent, if they primarily work in their workplace’s cold storage room. The supplement for hours worked in frozen storage rooms is 20 per cent.  

Ski resort industry’s collective agreement 

Employers must provide insulated work clothes (coveralls, gloves, and shoes) for snowmaking, ski-track making, and other outdoor work. The lowest allowed working temperatures are negotiated locally by the employer and their workers. 

Property services sector’s collective agreement 

A job’s difficulty and pay grade are determined according to the working conditions, including the temperature of the workplace. 

If the nature of the work or the working conditions require special work clothes or other equipment to avoid illness or injury, the employer is legally obligated to provide them for their workers, according to the Occupational Safety and Health Act. 

The employer must pay for all protective clothing and equipment required to ensure complete occupational safety. 

Legislation 

Occupational Safety and Health Act (pdf) (738/2002) 
Section 25: Avoiding and reducing workload factors 
Section 33: Ventilation in workplaces and volume of workrooms 
Section 39: Physical agents and electrical safety 

Rakennusten sisäilmasto ja ilmanvaihto, Määräykset ja ohjeet 2010 D2 (pdf, in Finnish) 
“Thermal conditions” or “thermal environment” is a specific design value for the temperature of the occupied zones of buildings. The design value is 21 °C in the heating season and 23 °C in the summer. Further guideline values have been set for certain spaces. 

Section 12 of the Government Decree on Workplace Health and Safety Requirements (577/2003) requires all workplace windows and glass walls to protect workers against harmful heat stress caused by the sun. This must be achieved by the window’s material or external protection. 

Useful links 

• Thermal conditions (Occupational Safety and Health Administration) 
• Thermal conditions at work (Finnish Institute of Occupational Health)