There were, in fact, excess deaths during the 2022 heatwave in the U.K. and Europe

Context

In a clip circulating on Facebook from a GB News broadcast aired on July 6, 2023, climate activist Alex de Koning from Just Stop Oil was confronted by anchors Andrew Pierce and Bev Turner. 

In the segment, de Koning quoted the World Health Organization (WHO), stating that 1,700 people had died in the U.K. during the summer 2022 heatwave. The presenters disputed this claim, displaying a statistic on excess deaths in the U.K. by month in an attempt to prove that more people die in cold weather than in warm. 

The anchors also ridiculed de Koenig's claim that temperatures may eventually become high enough that sweat will no longer cool humans down, causing them to "literally boil in [their] own sweat." 

In Fact

The U.K. Office for National Statistics recorded nearly 1,700 extra deaths in the week of July 16 – 22, 2022, compared to expected five-year average figures. Similarly, 56,303 deaths occurred in England and Wales during five different periods of heat between June and August 2022: 3,271 deaths (6.2 percent) above the five-year average for the same period. The average number of deaths per day was also higher compared to colder times of the year. Science journal Nature gives a similar figure of 3,469 deaths for the period and 70,000 excess deaths across Europe. 

Eirik Newth, astrophysicist and member of the Norwegian governmental climate committee, told Logically that the excess heat-related deaths in Europe have been mostly older people and those with underlying conditions. He points to asthmatics, who are affected by hot and stagnant air during heat waves, which increases pollution. 

Newth gives the example of Spain, where temperatures often do not dip below 30 degrees Celsius overnight. This, he explains, "strains the body, which has to go into overdrive to handle it and maintain a normal temperature, and may cause a heat stroke or heart failure." He adds that this is especially true in Southern Europe, where there are high temperatures and large cities, stating that "heatwaves especially affect large cities because of what is called the heat island effect." 

While the number of deaths in cold months was higher than in summer, even in 2022, Newth says the scenarios are not comparable because they ignore climate change's real consequences. 

As temperatures increase and collide with high moisture levels, the human system may be unable to cool down through sweating. This phenomenon can be measured with what is known as a "wet bulb" thermometer, which accounts for humidity as well as temperature and can be as basic as a thermometer wrapped in a wet cloth. 

In hot and dry conditions, it will show a lower temperature than the surroundings because the evaporating water from the cloth cools the air immediately surrounding it. When the humidity level rises, the wet bulb will show a higher temperature which increasingly resembles the surrounding air temperature, as the air is already saturated with moisture, preventing evaporation. Today, wet bulb temperatures are more commonly calculated at weather stations with the help of electronic instruments.

Sweating will cool the human body in warm and dry conditions, as the evaporation of sweat takes off excess heat. However, high wet bulb temperatures can create conditions where sweat on the skin evaporates slowly or not at all.  

"Even if it does evaporate, the minimal cooling is not sufficient to reduce body temperatures to the necessary 36 degrees Celsius, leading to heat-related illness and eventually mortality if exposure continues," explains Colin Raymond, Assistant Research Scientist at the University of California and NASA Jet Propulsion Laboratory. 

According to Raymond, the median estimate is that the wet-bulb temperature becomes dangerous for humans at approximately 35 degrees Celsius for six hours. A study co-authored by Raymond observes that some coastal subtropical locations have already reported short spells of conditions of 35 degrees, and the frequency of extreme humid heat has also more than doubled since 1979. 

Raymond does point out to Logically Facts that such conditions have not yet been reported in Europe, and "the health risks in most of Europe derive from the hot and dry type of heat."

The Verdict

Evidence shows an excess of deaths in the U.K. during the 2022 heatwave. Increased heat may cause lethal wet bulb temperatures where sweat no longer cools the body. Therefore, we have marked this claim as false.