Extreme Heat

Since 2004, the National Plan for Preventive Actions against the Effects of Excessive Temperatures on Health has been activated every summer, between the months of May and September.

To ensure the effective implementation of the Plan, the Interministerial Commission carries out the duties as designated in Order PRE/1518/2004 of May 28 .

Exposure to high ambient temperatures can lead to an inadequate response from the human thermoregulation system. Excessive heat can disrupt vital bodily functions if the body is unable to compensate for internal temperature changes.

From a biological perspective, exposure to extreme heat can cause health issues such as cramps, dehydration, heat exhaustion, and heatstroke (with multi-organ complications that may include symptoms like impaired gait, seizures, or even coma). The impact of excessive heat exposure is influenced by physiological aging and pre-existing health conditions.

Generally, a healthy individual can tolerate an internal temperature variation of about 3ºC without significant physical or mental impairment. At 37ºC, the body initiates a physiological defense response. Older adults and children are more sensitive to these temperature changes.

From a social perspective, marginalization, isolation, dependency, disability, and poor living conditions among low-income individuals add risk factors that make these groups even more vulnerable.

The National Plan outlines measures to reduce the health effects associated with extreme temperatures and to coordinate the institutions of the Public Administration involved. It also proposes actions that can be taken by Autonomous Communities and Local Administrations based on the assigned risk levels according to temperature thresholds.

• Health impact of high temperatures (Spanish)
• Reference threshold temperatures for health impact due to high temperatures (Spanish)
• Health risk levels due to high temperatures (Spanish)
• Preventive actions for high temperatures (Spanish)
• Daily Mortality Monitoring System (MoMo) (Spanish)
• General recommendations for protection and prevention against excessive temperatures (Spanish)
• Publications (Spanish)