Climate Change: The Possible Effects of Rising Temperatures on Children’s Health

[This text was originally published in Catalan in Diputació de Barcelona’s EspaiS@lut bulletin.]

In recent years, we have seen growing awareness about the dangers associated with high temperatures and concern about the consequences of this phenomenon. This is not surprising, given that the intensity, frequency and duration of heat waves have been increasing steadily since the 1950s. Furthermore, future predictions are pessimistic given that current heatwave trends indicate that the situation is set to worsen over time. The multiple effects of high temperature on our health and well-being tend to be underestimated, as does the public health problem posed by heat in the urban setting. The situation is further exacerbated by the shift towards increasing urbanisation of world populations and the growing number of urban heat islands in our cities.

The multiple effects of high temperature on our health and well-being tend to be underestimated, as does the public health problem posed by heat in the urban setting

Every year, with the advent of hotter summer weather, we are targeted by messages from a variety of sources advising us to avoid risky exposure to excessive heat. The most common recommendations include keeping ourselves cool and hydrated, seeking shade outdoors and cool spaces indoors. In addition, our body activates thermoregulatory mechanisms that help to maintain a balance between our core body temperature, which is around 36.5°C, and the external ambient temperature.

For a long time, it was erroneously believed that this thermoregulatory system was less efficient in children, a notion that has now been disproved thanks to recent evidence.

However, under extreme conditions the body’s thermoregulatory capacities can be altered. Physiological and environmental stressors, including pollution, obesity, diabetes, and other comorbidities, may be aggravating factors. At any rate, the results of some studies indicate that heat affects children’s bodies differently from those of adults. Children have a smaller body mass to surface area ratio than adults, making them particularly vulnerable to extreme heat.

The results of some studies indicate that heat affects children’s bodies differently from those of adults

In addition, their activity patterns, often characterised by hours of outdoor play, can involve more heat exposure and a greater risk of heat stroke and exhaustion. In addition, children may be unaware of the need to limit exertion during hot weather and to rehydrate, which can give rise to situations of risk.

The authors of a recent study in the United States of the effects of rising temperatures on the health of children and adolescents aged under 18 found, for the first time, that days with higher temperatures during the warm season were associated with higher numbers of hospital visits by children and adolescents. Moreover, around 12% of all emergency department visits in this cohort could be attributed to high temperatures.

The main causes for visits were heat stress and heat exhaustion, but they also included bacterial enteritis, possibly related to heat-related changes in habits; for example, bacterial infections could be caused by the consumption of food in a deteriorated state resulting from a lack of refrigeration. Interestingly, the study also reports that, in young populations, hospitalisations for blood and immune system disorders and nervous system diseases also increased during periods of extreme heat, an anomaly not so easily explained by changes in habits.

Children and adolescents spend much of their time in school every day. In the school environment, they live and grow together and are exposed to external phenomena that may affect their health, including high temperatures. It is, therefore, vital that the educational facilities where they spend so much of their time are adapted and equipped for the climate forecasts.

Schools as Climate Shelters

To meet the challenge of rising temperatures, Barcelona City Council, supported by funding from Urban Innovation Action (UIA), has decided to create a network of climate shelters, including schools. These refuges provide shelter for both children and the rest of the population, who can now enjoy spaces that protect them from the heat. In fact, it is estimated that by 2100 the city of Barcelona—an urban area particularly susceptible to heat islands due to its climate and dense urban fabric—will have 30 more days a year with temperatures over 30ºC as well as an increase of 3.5ºC in extreme temperature, taking the maximum to 42.8ºC.

Extreme heat has been linked to negative effects on learning in children. The project has therefore included interventions in 11 schools in Barcelona that were considered to be particularly vulnerable to heat. These measures included the creation of three types of infrastructure: blue (water points), green (spaces offering shade and characterised by vegetation), and grey (works on buildings to improve insulation).

It is estimated that children bear 88% of the burden of disease related to climate change, with the poorest populations being the most affected

Of particular note was the creation of multifunctional fountains, new plantings and green spaces as well as the installation of pergolas and solar protection in some schools. The functionality of some of these infrastructures has, however, been affected by COVID-19 restrictions.

Globally, it is estimated that children bear 88% of the burden of disease related to climate change, with the poorest populations being the most affected. It should be borne in mind that exposure to extreme heat-related events during childhood may have long-term effects that are as yet unknown. It is essential therefore to create greater awareness of the danger that such phenomena pose for the community as a whole and especially for very vulnerable groups, such as children, and to minimise such exposure and the risks it entails.