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, daily readings from 181 monitoring stations across the country have been used for temperature. In previous years, the model was based on 32 measuring stations assigned to the 40 largest localities.
High ambient temperatures, especially in combination with high humidity, are associated with significant health risks. The elderly, children, patients with cardiovascular and mental illnesses, and people with limited mobility are particularly susceptible.
|Summer||Heat-associated excess mortality||95% confidence interval (CI)|
Estimates of heat-associated excess mortality including 95% confidence interval, Austria, summer periods, 2016-2022. Estimates presented here are subject to change as a result of model adaptations.
The mortality of the population 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 very well documented statistically over decades - so well that very accurate estimates of expected deaths can be modeled for each calendar week.
This modeling of mortality is exploited by the European system for continuous mortality monitoring(Euromomo Mortality Monitoring): several European countries, including Austria, feed weekly all-cause mortality data into this system. This makes it possible to show whether the number of observed deaths is higher than the statistically expected number. Graphically, the mortality of the population presents itself in a typical wave-like progression. If there is an increase in deaths, outliers ("spikes") appear in the crests or troughs of the waves - this is referred to as excess mortality, which often correlates with the influenza epidemic in winter and with extreme heat events in summer.
The results presented are based on case-based mortality data and daily measurements of maximum and minimum air temperature from the Central Institute for Meteorology and Geodynamics (ZAMG) from 181 monitoring stations across Austria. Data on all-cause mortality were obtained from Statistik Austria.
Weekly all-cause mortality was modeled using 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 conducted in-depth analyses using different definitions of "hot and cold weeks." The definitions below best explain the all-cause mortality:
- Hot week: weeks with hot nights and using the temperature (daily minimum) of the hottest night of that week as a reference value once it is above 18 °C (following 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 that week.
The impact of SARS-CoV-2 was controlled in the model used for 2021 and 2022 by using the Goldstein indicator of those over 65 years of age (which is the weekly incidence of the age group multiplied by the weekly positive rate of reported tests).
Heat mortality monitoring is performed by us in Austria: It is based on statistical time-series analyses, which experience has shown to be very accurate and which have long been used to estimate influenza-associated mortality as well. These analyses incorporate case-based all-cause mortality data and daily maximum and minimum air temperature measurements obtained from 181 monitoring stations throughout Austria. The all-cause mortality data are from Statistics Austria.
The statistical model was developed by us in collaboration with the Graz University of Technology. The Austrian heat mortality monitoring is continuously improved by us. Further factors like humidity, wind speed, but also fine dust pollution or observations on infectious diseases etc. will be included in the model. In the final stage, it will 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 provinces and district administrative authorities will be able to promptly notify care facilities, hospitals, health resorts, kindergartens, mobile care services, doctors or emergency organizations of an increased need for care.
Protect food from the heat
You can find more information here.
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.)
- 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.
Last updated: 10.10.2023