CHALLENGE

Extreme temperatures have serious and direct effects on public health. In the summer of 2013–2014 Argentina experienced record heatwaves and preventable deaths. This motivated additional studies of the impact of extreme heat on health, with the aim of developing a health impact-based warning system.

Two studies established the statistical relationship between the occurrence of extreme temperatures and the increase in mortality. The studies were carried out jointly by the Ministry of Health, the National Meteorological Service, the National University of Entre Ríos, the National University of La Matanza and the University of Buenos Aires.

Mortality was analysed by sex, age and cause of death, and results indicated that mortality increased significantly in both extreme hot and cold temperatures. The mortality risk during heatwaves increased in 13 of the 18 provinces analysed. For extreme cold temperatures, risk of death significantly increased in the week following a cold day in 10 of the 21 cities analysed, while cold waves were associated with an increased risk of death in the following two weeks in 10 cities. Based on the evidence of extreme temperature episodes in Argentina driving increased negative health outcomes, an early warning system (EWS) for extreme temperatures was deemed necessary to reduce preventable deaths.

APPROACH

The objective of the EWS for extreme temperatures is to enable the population, the health system and civil protection organizations to take the appropriate prevention, mitigation and response measures at each alert level. Development of the EWS occurred in several phases.

Firstly, an EWS for Heatwaves and Health was developed and tested in two cities.132 Subsequently, in 2017 and based on the results of a study,133 the alert thresholds were adapted.

Finally, in 2021, the EWS began to cover the entire national territory (sub-divided into 168 fixed regions) and was renamed the EWS for Extreme Heat Temperatures. In the same way, the EWS for Extreme Cold Temperatures was created. The system issues alerts at different levels (yellow, orange and red). The alert thresholds were established based on the 90th percentile for heat (and the 10th percentile for extreme cold) of each city.

RESULT

During the warm period from October 2021 to March 2022, 987 daily alerts were issued for extreme heat (615 yellow, 205 orange and 167 red). Likewise, during the EWS for Extreme Cold Temperatures test period, from 9 June to 20 September 2021, 239 daily alerts were issued for extreme cold (197 yellow, 37 orange and 5 red).

The alerts were communicated to health and civil protection agencies at the national level, as well as to the general population through different media. An evaluation of the effectiveness of the system is planned. Under this system the weather alerts are issued by the Argentinian National Meteorological Service, and the Ministry of Health issues recommendations for health care.

LIMITATIONS AND LESSONS LEARNED

The Early Warning System for Extreme Temperatures (SAT-TE in Spanish) has climatic thresholds for which the significant increase in mortality was evaluated epidemiologically. Two studies established the statistical relationship between the occurrence of extreme temperatures and the increase in mortality.

However, future studies could evaluate the temperature at which mortality increases significantly, both for extreme cold and extreme heat. The main actions carried out are preventive, with little development of those aimed at mitigation and response. There is still a long way to go to complete the system, including improving the criteria for issuing alerts so that they contemplate different scenarios, such as power cuts or water shortages, among others.

During the warm period from October 2021 to March 2022, 987 daily alerts were issued for extreme heat.

PARTNERS: Ministry of Health of Argentina