Recommendations for indoor workplaces

On hot summer days the air temperatures in work rooms such as offices, shops, and workshops can rapidly reach "detrimental" levels, causing employees to suffer from the heat. The consequences of excessively high indoor air temperatures range from declining performance and enthusiasm for work, fatigue, and poor concentration to increased perspiration and strains on the cardiovascular system. What is more, studies demonstrate a noticeably increased risk of accidents occurring.

The legal situation

The Workplaces Ordinance (Arbeitsstättenverordnung, ArbStättV) of August 2004 requires healthy room temperatures for work rooms and protection against excessive solar irradiation, but a maximum permissible temperature is not specified. Para. 3 of subsection 4.2 of Technical Rule for Workplaces (Arbeitsstättenregel) ASR A3.5, Room Temperature (Raumtemperatur) of June 2010 stipulates that the air temperature in work rooms and social rooms is not to exceed +26°C. In addition, the kind of "summer scenario" described above is dealt with by a separate subsection (4.4) of ASR A3.5. It describes a banded model, including the parameters that are to be observed and the measures necessary to protect employees when outdoor air temperatures are higher than +26°C. Employees may continue to work at workspace air temperatures in the bands up to +30°C, up to +35°C, and above, provided the employer takes suitable protective measures. Despite these provisions, employees have no direct legal entitlement to, for example, air-conditioned rooms or time off in excessively hot conditions. Under Section 4 of the Occupational Safety and Health Act (Arbeitsschutzgesetz, ArbSchG), however, employers are obliged to design work in such a way that any risk to life and health is avoided as far as possible and any remaining risks are kept at low levels.

Since, under certain circumstances (e.g. increased work intensity and insulating clothing), there may be risks to health (e.g. strain on the circulatory system), protective measures are necessary at room temperatures above +26°C of the kind that can occur in works rooms without air conditioning in summer. Relevant parameters and examples are discussed in ASR A3.5. Protective measures are to be stipulated individually on the basis of a risk assessment conducted according to Section 3 of the ArbStättV.

Employers and employees have to respond appropriately to the situation, taking suitable measures by mutual agreement. Various technical, organisational, and personal measures can make a contribution, but so too can each individual’s personal conduct.

Cooling and protection against overheating

• Use night cooling: Ensure rooms are thoroughly ventilated (most effectively by cross ventilation with open windows and doors on opposite sides of a room) during the hours of night or - if the windows cannot be left open overnight for security reasons - in the early morning.
• Reduce or eliminate internal heat sources: Only operate electrical devices (e.g. lights, PCs, 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 tolerate the draughts they sometimes create. Dust or pollen can also be stirred up by their operation (a hazard for allergy-sufferers!).
  Basic advice on the procurement of fans, where to position them in rooms, and how to operate them in workplaces can be found here: https://verbraucherfenster.hessen.de/nachhaltigkeit/kaufen-verkaufen/mit-ventilatoren-gegen-die-sommerhitze
• 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 the risk of employees suffering “heat shock” when they go outside. In practice, a difference of about 6 K has proved to be a good solution. If air-conditioning systems are not operated correctly, employees’ health may be affected, by draughts or contamination with 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". The operating instructions are to be followed strictly, particularly with regard to possible room/space 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. External shutters or rear-ventilated awnings are highly effective, for example. Interior roller blinds should be made of lightly coloured and/or highly reflective materials. Furthermore, these sun protection features offer effective protection against glare.

Organising the work according to the weather

• 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 move work to different times.
  • Avoid overtime.
• Plan measures in good time: This should be done in consultation between the employer, the occupational physician, occupational safety and health specialists, and the works council/staff council.
• Raise employees’ awareness of heat stress in the workplace (information, advice, training).
• Make allowances for particular 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 on medication.

Adapting personal measures and the 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 cooling methods, 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 workplaces with permanently hot conditions.
• Drink enough liquids: You should drink in good time before you start to feel thirsty and drink sufficient quantities. The normal required daily water intake for an adult 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: Drinking water, (lightly carbonated) mineral water, 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 small sips because they cause the body to 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" (juice drinks made of pureed fruit) tend to be more like small meals.
• Eat sensibly: Do not consume rich, heavy meals. Easily digestible fruit and vegetable salads are ideal. Ask for chilled soup or just order small portions. 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.

Spot and prevent heat-induced health conditions

Health conditions such as heat exhaustion or heat collapse can also occur in overly warm offices. The signs of these conditions should be spotted in good time and immediate measures taken.

• Heat exhaustion is the body’s reaction to an excessive loss of water and salts, which are contained 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 with which it is associated. When this condition occurs, the supply of blood to the brain is reduced to a point where the patient may suffer short periods of unconsciousness and collapse.
• What to do:
  • If their symptoms get worse and persist for some time, call an ambulance. Until the ambulance arrives, the patient is to be positioned comfortably in cool surroundings or put into the recovery position if they lose consciousness. Also check their pulse and breathing so that cardiopulmonary resuscitation can be initiated if necessary. Where available, an automated external defibrillator (AED) can be used in an emergency. It 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. These devices should only be used by trained personnel. Defibrillators can be found in many public places these days (e.g. at airports, railway stations, etc.).
  • Move the patient 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.

Outdoor workplaces

Protection against solar UV radiation

Apart from 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. However, it is also a cause of skin and eye diseases. Although sunburn usually heals well, every time it is suffered, it increases the risk of developing skin cancer. This is a major health risk that can have fatal consequences, which is why protection against the sun is an important part of occupational safety and health.

The Occupational Safety and Health Act (sections 4, 5, 11, 12), the Workplaces Ordinance (Section 3a, Annex subheading 5.1), and DGUV Accident Prevention Regulation 1 (previously BGV A1; section 23) place obligations on employers to protect their employees against solar UV radiation.

The UV index (UVI) can be a helpful tool for risk assessments and contribute to the easy identification of hazards. UVI is a measure of erythemal solar UV radiation and is published online, by the Federal Office for Radiation Protection (Bundesamt für Strahlenschutz, BfS) for example. (Link: https://www.bfs.de/EN/topics/opt/uv/index/index_node.html) Generally, the higher the UVI, the greater the exposure to UV and therefore the bigger the risk of suffering sunburn. Once the UV index goes up to 3 or higher, you should protect your health by not exposing your skin and eyes to direct sunlight.

• Work in the shade if possible.
• Wear clothes that cover your body and sunglasses, put on a head covering, use sun protection products.
• Protect yourself against particularly intense solar irradiation by avoiding outdoor activities between 11 a.m. and 3 p.m. (summertime in Germany).

A sun protection product with a high sun protection factor (at least SPF 30) can noticeably reduce skin damage. It is important for sun protection products to be applied correctly and at regular intervals. Only then do they provide effective protection. The amounts people apply to their skin are often too small, which reduces the products’ protective effect.

The UV-A radiation that affects the eye is absorbed by the eye lens. After many years of exposure, a cataract may form. This is an opacification or clouding of the eye lens. Unlike most other human tissues, the eye lens is not capable of regenerating and has to be replaced with an artificial lens if the clouding is severe in order to preserve the patient’s visual acuity. Suitable sunglasses should therefore be worn in bright sunlight. For an appropriate protective effect, sunglasses in Filter Category 2 or 3 with a CE mark should be used. If the lenses cover enough of the eye, they offer almost 100% protection against UV radiation. Helpful tips on this topic are 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). Further important advice can be found on the page about protection against solar UV radiation in the workplace (see below).

Additional advice for outdoor workplaces

Apart from the recommendations for indoor workplaces given above, attention is to be paid to numerous influential factors where employees work outdoors, including 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 influences 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.

Construction 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 construction 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 that symptoms of heat-induced conditions are spotted.

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 curtailed or avoided completely. The latest measurement data and advice on what to do can be viewed on the Federal Environment Agency (Umweltbundesamt, UBA) website.

Fluid intake

It is to be ensured 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 supplied in the immediate working environment.

Heat-induced conditions

Especially when they are working outdoors, heat-induced conditions represent an increased risk to employees’ health. Apart from sunstroke, heatstroke is also possible in extreme cases. Further information and advice about what to do can be found in the report Information on the Health Impacts of Summer Heat and Heatwaves and Tips for Precautionary Health Protection (Informationen zu gesundheitlichen Auswirkungen sommerlicher Hitze und Hitzewellen und Tipps zum vorbeugenden Gesundheitsschutz), which is published by the Federal Environment Agency.

• Sunstroke (caused by sustained, direct exposure of the head and neck to solar radiation) Symptoms: dizziness, nausea, vomiting, neck pain.
• Heatstroke (the body’s cooling function fails, sweating stops) Symptoms: skin is dry, red, and hot, unconsciousness in the final stage. Heatstroke is a life-threatening condition.