Chamber of Labor demands statutory "heat break" and stricter rules for indoor workplaces

Study: PHS Index as a basis for measurement

Using the so-called PHS Index (Predicted Heat Strain, Ger.: predicted heat strain), not only temperature but also humidity, solar radiation, clothing, and physical exertion are taken into account. It is an occupational medicine model used to calculate how strongly heat stresses the human body and how long a person can safely work under certain conditions. Based on more than 17,000 calculations, it is possible, according to Hutter, to determine how long one can safely work under certain conditions and when breaks are required.

Under extreme heat stress with a perceived temperature of over 40 degrees, the safe working time can drop to just 15 to 20 minutes at a stretch, according to the study, before longer recovery breaks become necessary. "Vieles klingt einfach, in der Praxis braucht es aber genaue Überlegungen, wie dies umgesetzt wird", Hutter said. The perceived temperature does not only mean the actual thermometer value but depends on other factors as well. It is, for example, visible in some weather apps.

The AK's demands

Ines Stilling, head of the Social Affairs department at AK Vienna, said at a press conference on Monday: "Die neue Hitzeschutzverordnung ist ein wichtiger Erfolg, für den wir uns lange eingesetzt haben. Aber wir dürfen hier nicht stehen bleiben." She called for binding exposure limits and a mandatory "heat break" when there are health risks. "Hitzefrei sei allerdings das „allerletzte Mittel", Stilling emphasized.

Stilling also pointed out that while employees are obliged to perform work, "aber sie verpflichten sich nicht dazu, ihren Arbeitgebern ihre Gesundheit zu opfern". For the AK, the results are an argument for stricter legal requirements. Companies must be obliged to implement current occupational medicine findings and effectively protect employees from the consequences of increasing heat.

Existing regulations and exemptions

Since January 1, 2026, the Heat Protection Ordinance has applied to outdoor work, for example on construction sites. It is intended to protect against dangers from heat and UV radiation. A special arrangement exists on construction sites: here, work outdoors may be stopped at temperatures above 32.5 degrees Celsius if no cooler replacement workplace is available. However, the employer is obliged to take measures to protect health from a "perceived temperature" of 30 degrees Celsius.

The AK is calling, among other things, for a legally regulated "heat break" depending on physical strain, as well as paid cooling breaks. Technical measures are needed, such as providing cool rooms, but also organizational ones, such as shifting working hours to avoid heat, and personal ones, such as ensuring that sufficient fluids are available.

Around 400,000 people work outdoors in Austria. In Vienna alone, the 36-degree mark was exceeded on six days in 2025. Currently, there is no entitlement in Austria to leave the workplace on one's own even in high summer temperatures.

A look at indoor spaces and the ÖGB

Stilling also demanded binding regulations for indoor spaces, the mandatory use of scientific measuring devices in companies, and stricter inspections by the labor inspectorate. The Austrian Trade Union Federation (ÖGB) is also calling for better protective measures for indoor work in the heat.

Dinah Djalinous-Glatz, expert on worker protection at the ÖGB, pointed to increasing heat stress in indoor spaces such as hospitals, care homes, schools, and factory halls. The ÖGB launched a cross-industry online survey on current heat stress in the workplace to mark a heat action day. It takes the position that the same rules should apply to indoor work in the future as to outdoor work.

If a core body temperature of 38.5 degrees Celsius is reached, work must be stopped immediately and without exception. Heat stress is, in Hutter's assessment, not a marginal issue: "Hitzestress ist kein Spaß, aber nach wie vor aus meiner Sicht extrem unterschätzt." In the first year of UV-related white skin cancer being recognized as an occupational disease in Austria, 51 cases were reported.