Deadly Heat: The Night-Time Temperatures That Threaten Lives in Spain

The high temperatures brought on by the heatwave can make getting a good night’s sleep difficult, but prolonged periods of night-time heat can be deadly.

The issue of hot nightly temperatures becomes ever more relevant as Spain endures its third heatwave this year. With temperatures rising above 40 degrees in usually cool cities like Soria and Burgos, and night-time temperatures not dropping below 25 degrees, this heatwave, which began to escalate on Wednesday, is taking a toll on the most vulnerable, writes Nuis Diario.

The main issue is not a single day of rising temperatures but the persistence of this heat for several days in a row. ‘Many organs are being affected, many functions -above all, of populations at risk- that gives rise to an alteration of multiple organs or metabolic deregulation and, even, sometimes, multi-organ failure or early death,’ warns Lorenzo Armenteros, spokesman for the Spanish Society of General and Family Physicians (SEMG).

The Danger Is At Night

During the day, we can shield ourselves from the heat. However, many homes are not well conditioned, and it is the night that poses the most significant risk. Night-time temperatures above 20 degrees make it difficult to rest, and the elderly and babies suffer the most.

The problem is exacerbated by successive tropical nights. Jorge Olcina, a professor at the University of Alicante, explains that ‘The heat that kills is the night heat because it is the one that does not let the human body rest. It is an accumulator of effects.’

Hot Nights: A Growing Trend

A recent study in The Lancet warns that mortality rates can increase by up to 60 per cent during hot nights. This phenomenon has been growing in Spain, with 80 tropical nights recorded in 2022 in the Mediterranean regions and 59 in Madrid.

The mortality threshold differs by region, and those accustomed to cooler climates suffer more. In northern areas, temperatures of 26-30 degrees already have an impact, while the south has a higher tolerance.

Historically, fatalities were higher from cold than heat. However, since 2003, heat has become the more deadly factor, illustrating the progressive process of global warming.

The nocturnal heat that persists during heatwaves is revealing itself as a significant health risk. With global warming continuing its upward trajectory, the danger is unlikely to abate, leaving vulnerable populations at risk and highlighting the urgency of addressing climate change.