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.
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).
Heat-related mortality monitoring
Since the survey began in 2017, no higher figure for estimated heat-related deaths has been recorded in Austria than in 2026. The latest analysis by AGES puts the estimated figure for this period at 1,008 deaths.
Table 1: Estimated number of heat-related deaths in Austria by summer period (June to September) (2017–2026). Figures are given as point estimates with a 95 % uncertainty interval.
| 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 | 2026 |
| 639 (386–849) | 651 (384 – 889) | 754 (408–1031) | 327 (157–484) | 477 (281–665) | 569 (335–787) | 652 (399–875) | 989 (594–1330) | 425 (248–602) | 1008 (637–1293) |
As data from Geosphere Austria show, August 2026 was the hottest August in Austria’s 260-year history of weather records, with a new record temperature on hot days – 41.2 degrees and three consecutive days of 40 degrees or more. In July, the all-time July record set in 1983 was already significantly surpassed, with a temperature of 40.3 degrees. In June, the 35-degree mark was reached or exceeded at around half of all 277 weather stations.
Table 2: Estimated number of heat-related deaths in Austria for the summer period from June to September (2017–2026). Values are given as point estimates with a 95 % uncertainty interval.
| Federal state | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 | 2026 |
| Burgenland | 25 (-4 - 52) | 25 (-5 - 53) | 37 (-2 - 77) | 16 (-6 - 36) | 23 (-5 - 48) | 26 (-4 - 51) | 25 (-10 - 52) | 45 (-19 - 99) | 19 (-4 - 41) | 35 (-14 - 74) |
| Carinthia | 41 (-19 - 92) | 42 (-14 - 99) | 44 (-30 - 109) | 26 (-9 - 62) | 35 (-12 - 75) | 51 (-19 - 113) | 34 (-18 - 83) | 63 (-39 - 146) | 41 (-21 - 97) | 56 (-36 - 133) |
| Lower Austria | 142 (34 - 235) | 151 (23 – 263) | 185 (34 – 330) | 72 (-7 - 148) | 116 (10–209) | 122 (11–222) | 150 (37–256) | 227 (63–377) | 79 (4 – 152) | 223 (50–362) |
| Upper Austria | 107 (34–176) | 115 (35–186) | 125 (30–210) | 53 (1–104) | 71 (20–119) | 89 (22–153) | 118 (35–193) | 160 (48–262) | 67 (15–120) | 190 (63–303) |
| Salzburg | 35 (1–67) | 33 (3–62) | 40 (4–75) | 21 (0–43) | 22 (2–42) | 32 (4–61) | 32 (3–60) | 48 (4–87) | 28 (2–52) | 50 (-1 - 93) |
| Styria | 98 (1–187) | 82 (3–158) | 118 (-4 - 228) | 61 (-1 - 113) | 86 (2–160) | 93 (5–173) | 90 (-3 - 174) | 151 (-9 - 283) | 88 (9 – 165) | 123 (-23 - 243) |
| Tyrol | 33 (-11 - 72) | 33 (-6 - 72) | 32 (-18 - 74) | 21 (-4 - 43) | 21 (-5 - 46) | 33 (-8 - 70) | 34 (-18 - 78) | 48 (-12 - 105) | 34 (-10 - 69) | 49 (-19 - 113) |
| Vorarlberg | 28 (4 – 47) | 23 (3 – 43) | 30 (6 – 52) | 14 (-1 - 27) | 13 (2–24) | 24 (2–44) | 31 (8–53) | 30 (4–52) | 24 (5 – 42) | 53 (16–89) |
| Vienna | 130 (-32 - 267) | 148 (-44 - 312) | 143 (-67 - 319) | 43 (-74 - 151) | 89 (-57 - 205) | 99 (-59 - 233) | 139 (-5 - 266) | 216 (-20 - 421) | 45 (-63 - 152) | 229 (31 - 408) |
How AGES estimates heat-related deaths
It is very rare for a death certificate to list ‘heat’ as the cause of death. Heat can put strain on the heart, circulatory system, kidneys and lungs, and exacerbate existing conditions. The death certificate will then state, for example, ‘heart failure’. If one counts only the cases where ‘heat’ is recorded, the vast majority are overlooked. That is why AGES estimates the figure using a statistical model.
In Austria, people die every day – on average, well over 200. On very hot days and in the days that follow, more deaths are often recorded than when temperatures are moderate. The model examines this pattern and estimates the extent to which higher temperatures are associated with higher mortality rates. Based on this statistical correlation, it then calculates how many deaths can be attributed to the heat.
Statistik Austria provides the number of deaths per day and by federal state, regardless of the cause of death. GeoSphere Austria transmits weather data from 181 monitoring stations every 10 minutes. This data is used to calculate a daily ‘feels-like temperature’ for each federal state. In addition to air temperature, this takes into account humidity and wind, as 32 degrees in muggy air places a greater strain on the body than 32 degrees in dry air with a slight breeze.
Step 1: Understanding the effects of heat for each federal state
First, the daily temperatures and death tolls for each federal state are analysed separately. The model examines how mortality rates change at different temperatures.
However, the number of deaths is also influenced by other factors. The model therefore takes into account the seasons and longer-term changes. It also distinguishes between weekends and public holidays and weekdays. The years 2017 to 2019 and 2024 are used for the estimate. The years 2020 to 2023 were deliberately omitted, as the COVID-19 pandemic had a significant impact on mortality during this period.
The effects of heat may become apparent on the same day or only later. The model therefore considers the day of the heat event and the following 21 days. In doing so, it estimates how the relationship between temperature and mortality changes over time.
A rise in the number of deaths may be immediately followed by a fall. Such a pattern can occur, for example, if heat brings forward some deaths by a few days. The model can account for both changes. The subsequent fall may therefore reduce the overall estimated effect within this time window.
Step 2: The federal states learn from one another
In a small federal state such as Burgenland, only a few people die each day. Random fluctuations can therefore make it difficult to accurately estimate the relationship between temperature and mortality. For this reason, the results from all federal states are combined in the second step. This process takes into account the fact that some federal states have a higher proportion of older people than others. In this way, the models from the federal states support one another, and the estimates become more robust.
The model estimates, for each federal state, the temperature at which the fewest deaths are expected. Experts refer to this as the ‘minimum mortality temperature’ (MMT). In Vienna, it is 20.2 degrees; in Tyrol, 16.4 degrees. That may sound low, but it refers to the average perceived temperature throughout the whole day, including the night. It can be significantly hotter in the afternoon.
The MMT serves as a benchmark for the calculation. For every day with a higher temperature, the model estimates how much more frequently deaths occur compared with this benchmark temperature. It takes into account the day itself and the following 21 days. Based on this relationship and the actual observed death figures, a calculation is made to determine how many deaths can statistically be attributed to the heat. The estimated contributions are totalled across all days and federal states under consideration.
Table 3: Minimum mortality temperature and corresponding temperature percentile by federal state. The minimum mortality temperature (in °C) refers to the temperature at which mortality is lowest. The temperature percentile indicates which percentile of the temperature distribution this value corresponds to.
| Federal state | Minimum mortality temperature | Temperature percentile |
|---|---|---|
| Burgenland | 19.6 | 79.2% |
| Carinthia | 19.1 | 78.8 % |
| Lower Austria | 18.7 | 78.5 % |
| Upper Austria | 18.8 | 79.2 % |
| Salzburg | 17.6 | 79.6 % |
| Styria | 18.6 | 79.7% |
| Tyrol | 16.4 | 79.4 % |
| Vorarlberg | 17.4 | 79.9% |
| Vienna | 20.2 | 80.8% |
The result is an estimate, not a count. That is why AGES always provides a range that reflects the statistical uncertainty of the model used. For June to September 2026, the best estimate is 1,008 deaths. A figure between 637 and 1,293 is plausible. Where case numbers are small, such as in individual federal states, the uncertainty may be greater in relation to the estimated figure.
The model does not specify which individual died as a result of the heat. Nor does it provide any information on pre-existing conditions or the age of individual deceased persons. It estimates how many deaths across the entire population are linked to the heat.
This method is used internationally, for example in a major European study published in the journal *Nature Medicine*. This makes it easier to contextualise the figures for Austria within a European comparison. The results help to assess the extent of the health impacts of heat and provide a basis for heat protection measures.
The model underwent a fundamental overhaul between 2023 and 2025 and was updated to reflect the current state of scientific knowledge. Among other things, the new version allows for regional estimates at the level of the federal states. In addition to the changes to the model itself, the most significant adjustment is the switch from aggregated, weekly to daily weather and mortality data. Furthermore, the new model takes into account the delayed effects of heat, which can impact mortality for up to 21 days following a hot day. This makes the model more sensitive and better captures the cumulative risk of death during prolonged heatwaves. The estimates from the new model are comparable to those from an international study, although they are higher than those from the old model.
The different versions of the model are based on different methodological approaches and data sources, which is why their results are not directly comparable. Within a single model version, however, the estimates provide consistent and reliable insights into the temporal and regional effects of heat on excess mortality.
The revised model consists of two stages. In the first stage, statistical models are created for each federal state to describe the relationship between perceived temperature and mortality. These models are based on so-called Distributed Lag Non-linear Models (DLNMs), which also capture time-delayed effects. In the second stage, the differences between the federal states are analysed. These analyses yield the final models for each federal state.
A key concept is the so-called minimum mortality temperature (MMT). This is the temperature at which the calculated effect on excess mortality is lowest. If the temperature exceeds this level, the risk of heat-related deaths increases. The model estimates how many deaths are attributable to temperatures exceeding the MMT.
Table 3: Minimum mortality temperature and corresponding temperature percentile by federal state. The minimum mortality temperature (in °C) refers to the temperature value associated with the lowest mortality rate. The temperature percentile indicates which percentile of the temperature distribution this value corresponds to.
| Federal state | Minimum Mortality Temperature | Temperature percentile |
|---|---|---|
| Burgenland | 19.6 | 79.2% |
| Carinthia | 19.1 | 78.8 % |
| Lower Austria | 18.7 | 78.5% |
| Upper Austria | 18.8 | 79.2 % |
| Salzburg | 17.6 | 79.6 % |
| Styria | 18.6 | 79.7% |
| Tyrol | 16.4 | 79.4% |
| Vorarlberg | 17.4 | 79.9% |
| Vienna | 20.2 | 80.8 % |
Data sources
Daily mortality data and high-resolution weather data are used for the modelling. The mortality data are sourced from Statistics Austria and cover all causes of death. The weather data are provided by GeoSphere Austria and include 10-minute measurements from a total of 181 stations across Austria. The years 2020 to 2023 were excluded from the estimation of temperature effects, as the COVID-19 pandemic led to unusually high excess mortality during this period, which is not exclusively linked to heat during the summer months.
References
Gasparrini, A., Armstrong, B., & Kenward, M. G. (2010). Distributed lag non‐linear models. Statistics in Medicine, 29(21), 2224–2234. https://doi.org/10.1002/sim.3940
Janoš, T., Quijal-Zamorano, M., Shartova, N. et al. Heat-related mortality in Europe during 2024 and health emergency forecasting to reduce preventable deaths. Nat Med (2025). https://doi.org/10.1038/s41591-025-03954-7
Sera, F., & Gasparrini, A. (2022). Extended two-stage designs for environmental research. Environmental Health, 21(1). https://doi.org/10.1186/s12940-022-00853-z
The warmest year on record. Weather forecast for Austria. (n.d.). https://www.geosphere.at/de/aktuelles/news/waermstes-jahr-der-messgeschichte
Further information
Last updated: 09.11.2026
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