80% of Spaniards notice the increase in temperatures and associate it with climate change.

The Ministry of Health has commissioned a survey to understand the perception of the impact of extreme heat on people's daily life and health. The study, conducted by the consulting firm GAD3 between July 7 and 14, 2025, on behalf of the CSAI Foundation , gathers the opinions of 1,274 people over the age of 18, residing throughout Spain, with a margin of error of ±2.8% and a confidence level of 95.5%.

According to Héctor Tejero, head of the Health and Climate Change Observatory, "the results show a clear social awareness of the effects of extreme heat , as well as the need to strengthen protection and awareness measures against this increasingly frequent phenomenon in the context of climate change ."

Perception of extreme heat

Eight out of ten citizens (80%) say they have noticed a significant increase in extreme temperatures during recent summers, a perception that is heightened among women, young people, and residents of particularly hot provinces. Eighty-seven percent of respondents fully or partially link heat waves to climate change . Furthermore, the language used also influences the perception of risk: 47% believe that the expression "extreme heat" conveys a greater sense of danger than "heat wave" (27%).

Impact on health

More than 90% of the population considers extreme heat to be a serious health risk . The most frequently reported effects are heat exhaustion or fainting (84%), dehydration (83%), and insomnia or fatigue (70%), followed by nausea or dizziness (58%), worsening of chronic illnesses (56%), and confusion or disorientation (52%).

By age, people over 65 associate heat with the worsening of chronic conditions, while younger people highlight immediate symptoms such as skin irritation or general malaise. Thirty percent of the population considers themselves highly vulnerable to extreme heat . Twenty-five percent have personally suffered, or have experienced, some health problem during a heat wave. Of these cases, 53% required medical attention and 13% were hospitalized. The most common reasons for seeking medical attention were muscle cramps (68%), worsening of chronic conditions (60%), and heat exhaustion or dehydration (59%).

All of this data, Tejero says, "indicates that the population has a clear perception that extreme heat poses a threat to their own health , most likely based on direct and growing experience of discomfort due to rising temperatures in recent years."

Vulnerable groups

69% of the population identifies people over 65 as the most vulnerable group . Within this group, 81% identify as at-risk , primarily due to their age, medication use (26%), or chronic illnesses (20%).

In addition, the groups most identified as vulnerable include outdoor workers (57%), children under 5 years of age (38%), people with respiratory illnesses (28%), pregnant women (13%), homeless people (19%), and people without air conditioning or with low incomes (10%).

Among people belonging to a risk group (55% of the population), 31% consider themselves slightly or not at all vulnerable to extreme heat. According to Héctor Tejero, "this low perception of risk among vulnerable people highlights the need to continue strengthening awareness-raising efforts."

Inequality in thermal protection of homes

Only 23% of homes in Spain have adequate thermal insulation to protect against extreme heat. The most common resources in homes are fans (72%), awnings or blinds (69%), and air conditioning (55%). However, there are significant inequalities : in high-income households, air conditioning use reaches 62%, compared to 47% in lower-income households. Only 14% of the latter have good thermal insulation. Furthermore, 3% of homes lack any means to mitigate heat , a proportion that rises to 11% in cool areas of the country.

57% of the population has received or consulted official information about extreme heat, primarily through television (35%) and official websites (16%). Other relevant channels include social media (10%), health centers (9%), and family members or caregivers (7%).

The entities most frequently mentioned as broadcasters of this information are AEMET (36%) and the Ministry of Health (25%). The usefulness of the messages is highly valued: 90% of those who receive them find them useful , particularly those broadcast by social services (95%), radio (94%), and official websites or health centers (92%).

39% of the population checks the weather forecast more frequently during the summer, and this practice is even more common among those who have experienced heat-related health problems (57%) and residents of hot inland areas (45%).

For Héctor Tejero, "the survey brings good news: the high level of awareness of the impact of heat on health and its relationship with climate change . However, it still poses challenges for the coming years, such as getting people to increase their self-perception of vulnerability and implementing public policies that facilitate better adaptation to heat in homes, especially among those with lower incomes."