Working in buildings

On hot summer days, the air temperature can rapidly rise to levels that are unpleasant for employees in workspaces such as offices, retail shops, or workshops. The consequences of high indoor air temperatures range from declining enthusiasm for work, greater fatigue, and poor concentration to increased perspiration and cardiovascular strain. Studies have also demonstrated that the risk of accidents rises markedly.

Cooling and protection against overheating

• Use the coolness of the night: Ensure rooms and spaces are thoroughly ventilated (most effectively by cross-ventilation with open windows and doors on opposite sides of a room/space) during the hours of night or - if windows cannot be left open overnight for security reasons - in the early morning.
• Reduce or eliminate indoor heat sources: only operate electrical devices that produce heat (e.g. printers, scanners, copiers) as and when necessary.
• Fans (e.g. table, standing, tower, and ceiling fans) promote cooling by means of sweat evaporation, but not everyone will be able to tolerate the draughts they sometimes create. Dust or pollen can also be stirred up when they are in use (a hazard for allergy-sufferers!).
• If the building has an air-conditioning system, it should be set so that the difference between the indoor and outdoor air temperatures is not too great during hot weather. Otherwise, there is a risk of employees suffering “heat shock” when they go outside. A difference of about 6 K has proved satisfactory in practice. If air-conditioning systems are not operated correctly, employees’ health may be affected, by draughts or exposure to germs for example.
• Mobile air-conditioning units can also be deployed, in which case the associated capital costs and overheads have to be borne in mind. These systems can cause noise nuisance and there is a risk of draughts at the air outlets. The possible consequences may be a cold or a “stiff neck”. Their operating instructions are to be followed strictly, particularly with regard to rooms/spaces of different sizes and the routing of hoses to the exterior of the building.
• Protection against excessive solar irradiation: Disturbing, direct sunlight is to be avoided in the workplace. For example, external shutters or rear-ventilated awnings are highly effective. Interior roller blinds should be made of lightly coloured and/or highly reflective materials. These sun protection features also offer effective protection against glare.

Organise work in line with weather conditions

Work, working time, and break regimes should be adapted to the situation, within the limits of what is technologically or operationally possible:

• Avoid and/or reduce heavy physical work during the hot hours of the day and break it up with brief rest periods.
• Start work earlier.
• Fit in additional short breaks that last about ten minutes and, if possible, combine them with spending time or doing lighter activities in cooler areas.
• Use flexitime arrangements to reschedule work to different times.
• Avoid overtime.

Plan measures in good time: This should be done in consultation between the employer, the occupational physician, the occupational safety and health specialist, and the works council/staff council.

Raise employees’ awareness of heat stress in the workplace (information, advice, training).

Make allowances for specific groups: In particular, pregnant women, breastfeeding mothers, women at standing workstations, older employees, employees with health vulnerabilities (e.g. chronic illnesses), employees with certain disabilities, and employees who are taking certain medicines.

Adapt personal measures and behaviour

• Water can be used for cooling: Take arm affusions, apply cooling cloths and cold compresses, wet the skin, and take baths, showers, or footbaths if possible. These are highly effective ways of cooling the body, where they are practically feasible. Frequently holding your wrists under cold, running water is a simple, effective measure.
• Adapt the clothing you wear: Wear bright, air-permeable, loose, sweat-absorbent clothes to prevent heat building up. Choose light footwear. Make wearing ties optional.
• Special clothing: Special cooling vests and arm and leg sleeves are effective, but need to be accepted by employees (e.g. if worn in office workplaces) and are more suitable for permanently hot workplaces.
• Drink enough liquids: You should drink in good time (before you start to feel thirsty) and drink sufficient quantities. The required daily water intake for an adult normally varies between 1.8 and 2.5 l, depending on body weight and perspiration, and increases accordingly in hot conditions and when performing physical work. Do not drink too much all at once on hot days. It is better to drink small amounts frequently.
• Drinks on hot days: Gently cooled drinking water and mineral water (lightly carbonated), herbal and fruit teas, and diluted fruit juices (with mineral water) are particularly suitable things to drink. In addition to hydrating the body, they also replace electrolytes and minerals lost through sweating.
• Very cold drinks (ice cubes) should be avoided or only consumed in small quantities and little sips because they make the body produce more heat. Milk is not suitable for quenching thirst either because its high energy content tends to put strain on the organism rather than regulating the body’s liquid balance. Alcoholic beverages encourage diuresis, so should be avoided.
• If coffee or drinks that contain caffeine are consumed in the usual volumes, they will have no dehydrating effects, but should nevertheless only be enjoyed in moderation. Quenching your thirst with energy drinks is not to be recommended. Likewise, fashionable drinks such as smoothies (juices made from pureed fruit) tend to be more like small meals.
• Eat sensibly: Do not consume rich, heavy dishes. Easily digestible fruit and vegetable salads are ideal. Eat chilled soup or just half-portions of your usual meals. For example, eating a banana is an excellent way of restoring the body’s mineral levels. Be careful to make sure foodstuffs are stored properly because they can spoil quickly in very hot weather.

The legal situation

According to the Workplaces Ordinance (Arbeitsstättenverordnung, ArbStättV) and the relevant Technical Rule for Workplaces (Arbeitsstättenregel), ASR A3.5, the indoor temperature in workspaces is in principle not to exceed +26°C. At higher outdoor temperatures >+26 °C, a banded model with protective measures applies for indoor spaces:

• Up to +30 °C: measures recommended
• Up to +35 °C: measures required
• Over +35 °C: working only permitted with special protective measures

There are no entitlements to air-conditioned rooms/spaces or time off in very hot weather. The employer has, however, an obligation to prevent risks to health (Section 4 ArbSchG). Measures must be specified depending on the situation, ideally based on a risk assessment (Section 3 ArbStättV). Employers and employees are to take suitable technical, organisational, and personal measures jointly.

Working outdoors

When work is done outdoors, it is compulsory for suitable protective measures to be implemented on summer days. Apart from high temperatures, exposure to UV radiation from the sun and increased pollutant concentrations in the air also have impacts here.

Protecting the skin and eyes from UV radiation

Alongside light and thermal radiation, imperceptible UV radiation is also a part of the solar spectrum. It is, for example, responsible for skin tanning and the production of vitamin D, but also causes skin and eye diseases. Although sunburn usually heals well, every time it is suffered increases the risk of developing skin cancer. This is a major health risk that can have fatal consequences, which is why sun protection is integral to occupational safety and health.

The UV index

The UV index (UVI) can be a helpful tool, offering a yardstick for risk assessments and contributing to the easy identification of hazards. The UVI is a measure of erythemal solar UV radiation and is published online by the Federal Office for Radiation Protection (Bundesamt für Strahlenschutz, BfS), as well as being displayed in numerous mobile phone weather apps. Generally, the higher the UVI, the greater the possible exposure to UV and therefore the bigger the risk of suffering sunburn.

Measures

Employers have to take measures when the UV index is 3 or higher. Employees should also protect their skin and eyes from excessively strong solar radiation, for example by

• working in the shade if possible.
• avoiding outdoor activities when solar radiation is particularly intense between 11 a.m. and 3 p.m., if organisationally possible, and
• wearing clothes that cover the body and sunglasses, putting on a head covering, and using sun protection products on uncovered areas of skin.

A sun protection product with a sun protection factor of at least SPF 30 can noticeably reduce skin damage. It is important for sun protection products to be applied carefully, in sufficient quantities, and at regular intervals. The recommendation is 2 mg of sunscreen per square centimetre of skin. This is equivalent to approximately four heaped tablespoons for the whole body. Only then do such products provide effective protection. The amounts people apply to their skin are often too small, which reduces the protective effect. There are useful tips for the use of sunscreen at: Bundesamt für Strahlenschutz

Sunglasses in Filter Category 2 or 3 with a CE mark should be worn to ensure reliable protection of the eyes. If the lenses cover enough of the eye, they offer almost 100% protection against UV radiation. Helpful tips are also given in the Federal Institute for Occupational Safety and Health (Bundesanstalt für Arbeitsschutz und Arbeitsmedizin, BAuA) publication Sunglasses - Safe Sun Protection for the Eyes (Sonnenbrillen - Sicherer Sonnenschutz für die Augen) (German). Further important advice can be found on the page about protection against solar UV radiation in the workplace.

Further measures when work is done outdoors

• Building sites: Facilities that provide shade and can be used for ventilation or water-spraying (e.g. awnings, sunshades, etc.) are to be provided in particular at building sites.
• Working times, work rhythm, work intensity: Working times, work rhythms, and work intensity are to be adapted according to the weather conditions. For example, it should be examined whether work can be delayed or working times rescheduled to the cool morning hours, while the timing of rest breaks should be adjusted to take account of the strain workers are under.
• Employee training:
  • Raise employees’ awareness and draw their attention to the issues.
  • Organise first aid measures (develop an action plan).
  • Communicate information about hazards and precautionary measures.
  • Encourage staff to keep an eye on each other so they spot symptoms of heat-induced conditions.
• Pollutant limits: If the environmental authorities report ozone limits are being exceeded or summer smog is occurring, their recommendations are to be followed. In particular, heavy work is to be restricted or avoided completely. The latest measurement data and advice on the action to be taken can be viewed on the Federal Environment Agency (Umweltbundesamt, UBA) website.
• Fluid intake: Ensure suitable drinks are available at all times. Leaving a water bottle in a construction trailer, for example, does not make it possible to consume fluids regularly without leaving the workplace. Drinks should be accessible in the immediate working environment.

Where employees work outdoors, attention is to be paid to numerous factors that influence the situation, such as UV radiation, increased heat stress due to direct solar irradiation, and raised concentrations of air pollutants (summer smog, ozone, etc.), when risk assessments are conducted. Protection against these harmful factors is of the utmost priority if hazards to employees’ health are to be averted. Information about dangerous weather conditions and weather warnings can be found on the German National Meteorological Service (Deutscher Wetterdienst, DWD) website and elsewhere.

The legal situation

The Occupational Safety and Health Act (sections 4, 5, 11, 12), the Workplaces Ordinance (sections 3a, 6, Annex subheading 5.1), and DGUV Accident Prevention Regulation 1 (previously BGV A1; section 23) place obligations on employers to protect their employees from solar UV radiation. In addition, Occupational Medical Regulation (Arbeitsmedizinischer Regel) AMR 13.3 requires checks to ascertain whether workers are exposed to intense natural UV radiation and preventive occupational healthcare has to be offered.

Heat-induced health conditions

Whether in overheated office spaces or when working outdoors - employees can suffer various health conditions on hot summer days. The signs of these conditions should be spotted in good time and immediate action taken.

Typical conditions and their symptoms

• Sunstroke is caused by sustained, direct exposure of the neck and head to solar irradiation. The symptoms are dizziness, nausea, vomiting, and neck pain.
• Heat exhaustion is the body’s reaction to an excessive loss of water and salts, which are excreted in sweat. If these losses are not compensated for, symptoms such as weakness, warm, damp, pale-grey skin, muscle cramps, nausea and dizziness, confusion, fever, circulatory collapse, or unconsciousness may occur.
• Heat collapse is induced by increased circulation of blood to the skin to dissipate heat during persistent hot conditions and the critical drop in blood pressure to which it leads. When this condition occurs, the supply of blood to the brain is reduced to a point where the patient may faint for short periods and collapse.
• Heatstroke occurs if the body’s cooling function fails and sweat production ceases. The symptoms are dry, red, hot skin and, in its final stage, unconsciousness. Heatstroke is a life-threatening condition!

Please note: These various conditions cannot always be distinguished clearly from one another. Nevertheless, it is very important to take the right first aid measures!

Basic action to take

• Move the employee to a cool, shady place and keep calm.
• Give them small amounts of cool, non-alcoholic drinks that contain electrolytes.
• Apply cold compresses and make sure the patient is able to breathe fresh air. Give them a shower or bath if possible.
• Make sure they are wearing light, comfortable clothing. Remove unnecessary garments.

If their symptoms worsen or persist, call an ambulance. Until the ambulance arrives, the employee is to be positioned comfortably in cool surroundings or put into the recovery position if they lose consciousness. Also keep checking their pulse and breathing so that cardiopulmonary resuscitation can be started if necessary. Where available, an automated external defibrillator (AED) can be used in an emergency. The device gives instructions via a speaker, measures the patient’s heart rhythm to determine whether an electric shock will be necessary to resuscitate them, and automatically delivers the shock if required. They should only be used by trained personnel. Defibrillators can be found in many public places these days (e.g. at airports, railway stations, etc.).