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Recommendations for hot summer days in workplaces

Recommendations for workplaces in buildings

On hot summer days, it may quickly be the case that the air temperatures in working spaces such as offices, shops, or also in workshops increase to "detrimental" values and the employees suffer from the heat - the consequences include a reduced performance and motivation, fatigue and lack of concentration, through to an increased emission of sweat and cardiovascular strains. Studies demonstrate a significantly increased risk of accidents.

Woman drinks a glass of water © Uwe Völkner, Fotoagentur FOX

Legal situation

The Workplaces Ordinance (ArbStättV) from August 2004 requires room temperatures beneficial to the health for working spaces and the protection against excessive solar irradiation; however, a maximum admissible temperature is not specified. The workplace rule ASR A3.5 Raumtemperatur (room temperature) from June 2010 specifying this general requirement defines in item 4.2 section 3 that the air temperature in working spaces and staff rooms should not exceed +26°C. The "summer case" described above is additionally established in ARS A3.5 using a separate item. 4.4. For ambient air temperatures of more than +26°C, this item describes a step model including boundary conditions to be observed and the necessary protective measures for the employees. In this, the employees may continue to work at air temperatures in working spaces of up to +30°C to +35°C and more, provided that the employer takes suitable protective measures. Despite these new provisions, employees are not directly legally entitled to air-conditioned rooms or time off due to excessive heat, for example. Pursuant to § 4 Occupational Health and Safety Act (ArbSchG), the employer is obliged to organise the work in such a way that a danger to life and health preferably is avoided and remaining hazards are minimised, however.

Since room temperatures of more than +26°C, as possible in working spaces without air-conditioning in summer, may, under certain circumstances (increased work hardness and clothing situation), result in a danger to the health (e.g. circulation strain), protective measures are necessary. Boundary conditions and examples are mentioned in ASR A3.5. The protective measures must be defined individually with the help of a risk assessment pursuant to § 3 ArbStättV.

Employers and employees must master the situation by mutual consent with the help of suitable measures. Different technical, organisational, and personal measures, but also the personal behaviour of each individual person may contribute to the aforementioned.

Cooling and protection against overheating

Cooling and protection against overheating

  • Using the night-time cooling: provide for intensive ventilation of the rooms (most efficiently through transverse ventilation = opening of opposite windows and doors, respectively) in fact at night time or - if the windows may not remain open at night due to safety reasons - in the early morning hours.
  • Reduce or avoid internal heat sources, e.g. only operate electrical devices when necessary (lights, PC, printer, scanner, copy machine).
  • A table fan supports cooling through sweat evaporation, but the draught possible regarding this solution may not be tolerated by everyone. Furthermore, dust or pollen may be blown up by operating a fan (hazard for persons suffering from an allergy!).
  • If an air-conditioning system is present, the difference to the room air temperature should not be set too high in the event of high ambient air temperatures; otherwise, there is the risk of suffering a "heat stroke" when going outside. In practice, a difference of about 6 K has proved to be a good solution. If the air-conditioning devices are operated improperly, health impairments may occur, e.g. due to draught or germ load.
  • Mobile air-conditioning systems may also be used; the related investment costs and overheads must be taken into account. Noise pollutions may occur and there is the risk of draught at the air outlets. In this case, catching a cold or the neck becoming stiff cannot be excluded. The operating instructions must be observed exactly, particularly regarding the possible room size and the routeing of the hoses to the outside.
  • Protection against excessive solar irradiation: disturbing direct solar irradiation to the workstation must be avoided. For example, external shutters or back-ventilated awnings are very effective; roller blinds on the inside should be made of a bright and/or highly reflective material. These solar protection devices furthermore offer an efficient glare shield.

Organising the work according to the weather

Organising the work according to the weather

  • Work, working time, and break regimes should be adapted to the situation within the framework of what's technologically or operationally possible:

    • avoid and reduce and interrupt with short breaks labour during the hot periods, respectively
    • start working earlier
    • have additional short breaks of about ten minutes and, if possible, combine these with a stay or a non-exhausting activity in cooler areas
    • use flexible schedules to work at different times
    • avoid after hours
  • plan measures prematurely, in consultation between employer, company doctor, occupational health and safety practitioner and works/staff council
  • raise the employees' awareness for the subject of heat stress at the workstation (information, consultation, training)
  • consideration of special groups of persons: particularly pregnant women or nursing mothers, women at standing workstations, older employees and employees with vulnerable health (e.g. chronically sick persons), persons with a certain handicap and medical treatment, respectively

Adapting personal measures and the behaviour

Adapting personal measures and the behaviour

  • Water applications in the form of treatments for the arms, cooling cloths and compresses, wetting of the skin surfaces, possibly also baths, showers, or foot baths, are very efficient cooling methods, as far as they are practically applicable. Frequently having cool water flow over the wrists is simple and efficient.
  • Adapting the clothing: bright, air-permeable, casual, and sweat-accepting clothes in order to avoid heat accumulation, air-permeable shoes, make wearing ties an option
  • Special clothing, such as special cooling vests and arm and leg sleeves are efficient, but their acceptance must be provided for (e.g. wearing at office workstations) and they are rather suitable for heat workstations.
  • Drinking enough: one should drink early enough even before the thirst develops and sufficient amounts. The normal daily water requirements of an adult are, depending on the body weight and the emission of sweat, 1.8-2.5 L and increase accordingly during physical work and heat. On hot days, it is important to not to drink too much at once; it is better to drink low volumes frequently.
  • Beverages on hot days: specifically suitable beverages include: drinking and mineral water (with low amounts of carbon dioxide), herb and fruit tea, diluted fruit juices (with mineral water); in addition to the water, they also replace the electrolytes and mineral nutrients lost through sweating.
  • Very cold beverages (iced) should be avoided or drunk only in low quantities and small sips, since they cause the body to produce more heat. Milk also is an inappropriate thirst quencher, since the high energetic content rather strains the organism than balancing the liquid balance. Alcoholic beverages promote the loss of water of the body, i.e. these should be avoided.
  • If coffee or caffeine-containing beverages are drunk in the usual volumes, they have no dehydrating effects, but should only be drunk in moderation nevertheless. Using energy drinks as thirst quencher is not recommendable. Likewise, trendy beverages, such as the so-called "smoothies" (juices made of mashed fruit) are rather a small meal.
  • Eating deliberately: do not eat any heavy and rich meals; easily digestible fruit and vegetable salads are appropriate, only ask for chilled fruit soup or half of the portion. For example, a banana is absolutely suitable in order to quickly restore the mineral balance. Foodstuff must be stored properly in any case, since it may decay quickly at very high temperatures.

Identifying and avoiding health disorders caused by heat

Health disorders such as heat-related fatigue or heat collapse may occur in an overheated office as well. The signs of these disorders should be identified prematurely and immediate measures should be initiated.

  • Heat-related fatigue is the reaction of the body to an excessive loss of water and salts contained in the sweat. If these losses are not compensated for, symptoms such as weakness, pale-grey warm and damp skin, muscle cramps, nausea and dizziness, confusion, fever, circulatory failure, or unconsciousness may occur.
  • A heat collapse is induced by an increased circulation of the skin for heat dissipation during longer periods of heat and a related critical hypotension. In this condition, the brain circulation is reduced to a point where short periods of unconsciousness and a collapse may occur.
  • Basic rules of conduct:

    • bring the person concerned to a shady, cool location and keep calm
    • provide cool, electrolyte-containing, non-alcoholic beverages in small amounts
    • cooling compresses, provide fresh air, shower or baths, if necessary
    • light and comfortable clothing, remove unnecessary clothes
  • If the symptoms get worse and persist for extended periods of time, call an emergency doctor. Until the emergency doctor arrives, the employee must be positioned comfortably in a cool environment and in the lateral recumbent position in the event of unconsciousness, respectively. Heart rate and breathing must also be checked in order to prompt possible cardiopulmonary resuscitation. If present, an automated external defibrillator (AED) may be used in case of emergency. It uses a speaker to provide instructions regarding the behaviour, measures, prior to triggering the current impulse, whether there is a necessity for resuscitation, and automatically triggers it, if necessary. These devices should only be used by trained personnel. Defibrillators can be found in many public locations these days (e.g. at airports, railway stations, etc.).

Outdoor workstations

Protection against the UV radiation of the sun

Often, the hazards caused by intensive solar radiation are underestimated. In addition to light and heat, the invisible UV radiation also is a part of the solar radiation. It is responsible for skin tanning and for vitamin D production. But it is also a possible cause for skin and eye diseases. Even though a sun burn frequently heals well, every sun burn increases the risk of contracting skin cancer. A huge health risk that may have fatal consequences. As a consequence, the following is applicable: solar protection is occupational health and safety.

Worker on rooftop © iStock | sculpies

With the Occupational Health and Safety Act (§ 4, § 5, § 11, § 12), the Workplaces Ordinance (§ 3a, annex 5.1), and the Accident Prevention Regulation DGUV Regulation 1 (hitherto: BGV A1, § 23), there already are obligations for the employers regarding the protection of employees against solar UV radiation.

Within the framework of the risk assessment, the UV index may be an important variable and contribute to easily determining the hazard. The UV index (UVI) describes the erythemal UV radiation of the sun. In this, the following is applicable: the higher the UVI the higher the UV strain and therewith the risk of getting a sun burn. At a UV index of 3 and above, you should protect your health by the following:

  • Avoid unnecessary solar radiation to skin and eyes!
  • Work in the shade as far as possible!
  • Wear clothes protecting against the sun. (Do not work shirtless)!
  • Protect yourself specifically against the intensive solar radiation between 11 am and 3 pm (summertime in Germany).

Furthermore, a sun protection product with a high sun protection factor (at least SPF 30) may reduce skin damage significantly. In this, it is important that the sun blocker can be applied easily and is applied with a sufficient thickness. Only then efficient protection may be achieved. Frequently, the applied quantity is too low, which may result in the protective effect being decreased to one third.

The UV-A radiation affecting the eye is absorbed by the eye lens. After multiple years of exposure, a cataract may be formed. This is an opacification of the eye lens. As opposed to most of the other human tissues, the lens is not capable of regenerating and must be replaced by an artificial lens if the opacification is too strong. In Germany, about 600,000 cataract surgeries are performed that are partially attributable to too high a UV-A life dose.

Therefore, sunglasses should be worn if the solar radiation is strong. When purchasing sunglasses, observe the CE mark, filter category 2 or 3. If the eyeglass lenses cover the eye sufficiently, virtually 100 % protection against UV radiation is provided for. Helpful tips regarding this topic can be found in the pamphlet "Sonnenbrillen - Augen auf beim Brillenkauf!" (sunglasses - don't buy glasses on the fly).

Additional information for outdoor workplaces

When working outdoors, additional influencing factors such as UV radiation, increased heat load due to direct solar irradiation, increased concentrations of air pollutants (summer smog, ozone, etc.) must be observed within the framework of the risk assessment - in addition to the information listed in chapter 1 for workplaces in buildings. The protection against these detrimental effects is of the utmost priority in order to avoid any risk to the health of the employees. Information on whether a heat wave must be expected can be obtained from the German Meteorological Service (Deutscher Wetterdienst - DWD) by means of a heat warning program.

Construction sites

Specifically at construction sites, facilities for shading, ventilation, or water-spraying must be provided (e.g. awnings, sunshades, etc.).

Working time, work rhythm, work intensity

Adapt the working time and work rhythm, as well as the work intensity to the weather, e.g. check whether the work may be postponed, reschedule the working time to the cool morning hours, adapt break times to the stress.

Employee training

  • awareness-raising of the employees and increase their awareness
  • organise first-aid measures (develop an action plan)
  • convey information on the hazards and preventative measures
  • mutual observation regarding symptoms of heat diseases

Pollutant thresholds

If the environmental authorities report that the ozone values are being exceeded and that there is summer smog, respectively, their recommendations must be abided by, specifically heavy work must be limited or avoided completely. Current measured data and rules of conduct can be obtained from the Federal Environment Agency.

Drinking behaviour

The permanent availability of suitable beverages must be ensured. For example, the water bottle in the construction trailer is not a possibility for regularly drinking without leaving the workstation. Beverages should be provided in the direct working environment.

Heat diseases

Specifically when working outdoors, heat diseases are an increased hazard to the health; along with the sunstroke, a heat stroke is also possible in extreme cases. More detailed information and rules of conduct can be found in the report "Informationen zu gesundheitlichen Auswirkungen sommerlicher Hitze und Hitzewellen und Tipps zum vorbeugenden Gesundheitsschutz" (information on health-related effects of summer heat and heatwaves and tips for preventative health protection) of the Federal Environment Agency.

  • Sunstroke (caused by long-term, direct solar irradiation on head and neck) Symptoms: dizziness, nausea, vomiting, neck pain
  • Heat stroke (cooling function of the body fails, sweat production stops) Symptoms: skin is dry, red, and hot, unconsciousness in the final stage

To the topic

High room temperatures

What is permitted by the legislator and when the employer has to take measures

Find out more : High room temperatures …

Protection against UV radiation of the sun

Natural UV radiation puts outdoor workers at increased risk of cancer

Find out more : Protection against UV radiation of the sun …


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