Heat information

The heat telephone provides you with information on heat prevention

Heat telephone - Austria-wide free of charge: 0800 880 800


Heat waves are no longer an exception. They have a major impact on health. The elderly, children, patients with cardiovascular and mental illnesses, and people with limited mobility are particularly vulnerable. Our heat mortality monitoring helps to further develop strategies to mitigate the consequences of heat waves.

Heat mortality monitoring

Heat mortality monitoring can be used to model whether the number of observed deaths in Austria is higher than the statistically expected number. Since 2019, the daily temperature readings from 181 measuring stations throughout Austria have been used. In previous years, the model was based on 32 measuring stations, which were assigned to the 40 largest towns and cities. High ambient temperatures, especially in combination with high humidity, are associated with significant health risks. Elderly people, children, patients with cardiovascular and mental illnesses and people with limited mobility are particularly susceptible.

For the calculation of heat-associated excess mortality in 2023, the years of the Covid-19 pandemic (2020-2023/CW20) were excluded from the estimate of the long-term trend because unusually high mortality was observed during this period. However, an estimate of heat-associated excess mortality for the years 2020 to 2022 was still carried out.

The estimated heat-associated excess mortality in 2023 was 53 deaths, lower than the values for 2017, 2018, 2019, 2021 and 2022. With the exception of 2021, all summers were warmer than the summer of 2023.

Summer Heat-associated excess mortality 95% confidence interval (CI)
2016 0 -73; 73
2017 375 245; 505
2018 550 295; 806
2019 198 -41; 438
2020 0 -45; 45
2021 227 -10; 464
2022 231 -31; 493
2023 53 -161; 266

Estimate of heat-associated excess mortality including 95 % confidence interval, Austria, summer periods, 2016-2023.

Limitations: We would like to point out that the definitions of "hot and cold weeks" have a significant influence on the estimates of heat-associated excess mortality. It cannot be ruled out that the high excess mortality of previous years had an impact on heat-associated excess mortality in 2023 because the vulnerable group may have been reduced accordingly in the summer of 2023.

The population's mortality rate is not evenly distributed throughout the year, but is subject to seasonal fluctuations: More people die in the winter months than in the summer months. These fluctuations are statistically very well documented over decades - so well that very precise estimates of expected deaths can be modelled for each calendar week.

The European system for continuous mortality monitoring(Euromomo mortality monitoring) makes use of this mortality modelling: several European countries, including Austria, feed data on weekly all-cause mortality into this system. This makes it possible to show whether the number of observed deaths is higher than the statistically expected number. The mortality of the population is presented graphically in a typical wave-like pattern. If there is an increase in deaths, outliers ("spikes") appear in the wave peaks or troughs - this is referred to as excess mortality, which often correlates with the influenza epidemic in winter and extreme heat events in summer.

The results presented are based on case-based mortality data and daily measurements of the maximum and minimum air temperature from GeoSphere Ausria from 181 measuring stations across Austria. Data on all-cause mortality comes from Statistics Austria.

The weekly all-cause mortality was modelled using the air temperature during hot (summer) and cold (winter) weeks. Summer was defined as week 21 to 39, and winter as week 40 to 20. The definitions of "hot and cold weeks" have a significant impact on the estimates of heat-associated excess mortality. We have conducted in-depth analyses with different definitions of "hot and cold weeks". The all-cause mortality is best explained by the definitions given below. In the results, only the influence of hot weeks in summer is shown, but cold weeks in winter influence the long-term trend of the model:

  • Hot week: Weeks with hot nights and use of the temperature (daily minimum) of the hottest night of this week as a reference value as soon as this is above 18 °C (based on the definition of a tropical night).
  • Cold week: Weeks in which at least one day had a temperature (daily minimum) below 0 °C. The daily minimum of the coldest day was then used as the reference value for this week.

The influence of SARS-CoV-2 was controlled in the model used for 2021 and 2022 by using the Goldstein indicator of over 65-year-olds (this is the weekly incidence of the age group multiplied by the weekly positive rate of reported tests).

Heat mortality monitoring is carried out by us in Austria: It is based on statistical time series analyses, which experience has shown to be very accurate and have long been used to estimate influenza-associated mortality. These analyses include case-based all-cause mortality data and daily measurements of the maximum and minimum air temperature from 181 measuring stations across Austria. The data on all-cause mortality comes from Statistics Austria.

The statistical model was developed by us in co-operation with the Graz University of Technology. We are continuously improving the Austrian heat mortality monitoring system. Other factors such as humidity, wind speed, but also particulate matter pollution or observations on infectious diseases etc. are to be included in the model. In the final stage of development, it will also be possible to determine heat-associated mortality on a small scale. With this information, the Federal Ministry of Social Affairs, Health, Care and Consumer Protection, the federal states and district administrative authorities can promptly inform care facilities, hospitals, spas, nurseries, mobile care services, doctors or emergency organisations of an increased need for care.

Tips for hot weather

You should immediately

  • seek a cool environment
  • Drink fluids
  • Cool down your body with wet towels or by taking a shower.

If your symptoms do not improve, please call your doctor or the ambulance (emergency number: 144).

These symptoms may be due toheat accumulation: Heat accumulation can occur in high heat, especially in connection with physical exertion or wearing clothing that is too tight and too warm. The resulting heavy sweating can lead to a high loss of minerals and fluids and subsequently to circulatory problems. Typical symptoms of heat exhaustion are dizziness, lightheadedness and nausea, an elevated pulse and increased body temperature (up to 41 °C).

You should do the following immediately:

  • Move the affected person to a cool environment if possible
  • Loosen the person's clothing
  • Place wet cloths on the person's head and body
  • If the person is conscious, give them sips of fluid
  • If the person is unconscious, place them in a stable lateral position
  • Be sure to call a doctor or the ambulance (emergency number: 144).

It may be a case ofheat stroke. Heat stroke can be the result of heat exhaustion that has not been adequately treated. In addition to the symptoms of heatstroke, headache, vomiting and muscle cramps typically occur. Body temperature may rise to as high as 43°C.

In severe cases, confusion and even clouding of consciousness and possibly unconsciousness may occur. This is then a very threatening situation that can lead to failure of vital organs and ultimately to death, especially in elderly and weakened persons.

The following measures and rules of conduct can prevent heat accumulation or heat stroke relatively easily and effectively:

  • Create a tolerable room temperature
  • Ventilate early in the morning, in the evening and if possible also at night.
  • Darken rooms during the day (preferably with an external sunshade).
  • Hang damp cloths to cool rooms
  • Wear light and air-permeable clothing if possible
  • Avoid unnecessary exertion
  • Avoid dense crowds
  • Stay outdoors only briefly if possible, especially at lunchtime
  • Avoid direct sunlight on the body (use a sunshade or headgear with neck protection, walk in the shade, etc.)
  • If possible, you can cover your head and neck with damp cloths or shower/bathe more often or hold your forearms in cold water
  • Use fans
  • Seek out air-conditioned rooms if possible
  • Drink enough and consciously, not only when you feel thirsty (1.5 to 3 liters daily)

As drinks are particularly suitable:

  • tap and mineral water
  • diluted fruit and vegetable juices
  • unsweetened fruit and herbal teas

Strongly sweetened and alcoholic beverages are not suitable!

Important: drink sufficient quantities, at least 1.5 to 3 liters daily. For adults who perform strenuous activities, much larger amounts may be required; for children, smaller amounts may be sufficient.

Heavy sweating can also cause the body to lose significant amounts of minerals. This loss can be compensated for by consuming beverages containing minerals. Another option is to add some salt to beverages that have small amounts of minerals.

Caution: Persons with kidney or cardiovascular disease should be sure to consult their physician regarding the appropriate amount of fluids. This also applies to persons who must restrict fluid intake for medical reasons.

During periods of heat, large meals should not be eaten. Several small meals spread throughout the day are more digestible. Easily digestible and low-fat foods with a high water content are preferable. These include in particular:

  • Fruits and vegetables (melons, cucumbers, tomatoes, etc.)
  • Compotes
  • Salads
  • low-fat meat and vegetable soups
  • low-fat or diluted milk and dairy products (e.g. buttermilk with mineral water)

Fatty foods should not be consumed in high heat, and meat should only be consumed in small amounts.

For various reasons,infants, young children, the elderly and chronically ill, andpeople with disabilities are particularly at risk during hot spells. For example, the feeling of thirst decreases with age, which is why older people often consume too little fluid. Infants and small children still lack the ability to articulate themselves accordingly.

Family members, friends, neighbors, caregivers, etc. of people who are particularly at risk should therefore take great care to ensure that these people drink enough fluids and that other measures to prevent heat damage are taken or rules of conduct are observed.

Taking certain medications may have a negative impact on heat tolerance. In particular, the following medicines should be mentioned here:

  • Diuretics (dehydrating agents)
  • Benzodiazepines (sleep-inducing and strong anesthetics)
  • Sedatives (tranquilizers)
  • Beta-receptor blockers (often taken in combination with diuretics or other blood pressure-lowering agents).

If you need to take such medicines, be sure to consult your doctor or a pharmacist during hot spells.

Information on labor law provisions can be obtained from the Chamber of Labor (AK).

Last updated: 19.06.2024

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