Impact of extreme heat and heatwaves on children’s health: An investigation. Image credit: Piyaset / Shutterstock
As heatwaves increase, children’s health is increasingly at risk. This research reveals alarming links with premature births, asthma and emergency room visits, and highlights the urgent need for adaptive measures to protect the youngest and most vulnerable.
In a recent review article in Journal of Climate Change and HealthResearchers investigated the impact of heat waves and extreme heat events on children’s health and how children can adapt to these climate-related threats.
Their findings show that extreme heat exposure significantly increases the risk of preterm birth, low birth weight and asthma in children, highlighting the urgent need for research into adaptation measures to protect children’s health in a warming world.
Newborn outcomes and birth risks
The study found that extreme heat exposure during pregnancy significantly increases the risk of several adverse birth outcomes.
26 studies have shown that heatwaves and high temperatures during pregnancy are associated with preterm birth, stillbirth, premature rupture of membranes and low birth weight. For example, a systematic review found that exposure to extreme heat increased the risk of preterm birth by 16% and low birth weight by 31%.
The last week of pregnancy appears to be particularly at risk for heat, but the dangers are present throughout pregnancy. Studies have also shown that the risks are not evenly distributed – women of lower socioeconomic status (SES) and those in low- to middle-income countries are more likely to experience these negative outcomes.
In addition, there is better protection against these risks in wealthier areas and among mothers with higher education.
Emergency room visits and hospital stays
Extreme heat also leads to more frequent emergency room visits and hospitalizations, especially among children.
22 studies, conducted primarily in the United States and Australia, found that heat waves are associated with an increase in emergency department visits due to electrolyte imbalance, dehydration, and other heat-related illnesses.
Children from socioeconomically disadvantaged backgrounds were more likely to require medical care during such events. In the Australian city of Brisbane, for example, the number of infant hospitalizations increased significantly during severe heatwaves.
However, results have been mixed. Some studies, such as one from Japan, found no significant increase in hospitalizations of children due to heat-related complications.
Understanding heatwaves
Morbidity, mortality and respiratory diseases
The study showed that heatwaves lead to a range of health problems in children, including respiratory problems and, in some cases, increased mortality. For example, in Varanasi, India, children under the age of four were found to be particularly mortal during heatwaves.
In terms of morbidity, studies from China report that heatwaves worsen asthma symptoms in children. One study also found that poor air quality (as concentrations of particulate matter, carbon monoxide, nitrogen dioxide and ozone can increase during heatwaves) combined with extreme heat worsens respiratory diseases.
Extreme heat waves increase the risk of infectious diseases, especially during European water-based recreational activities. Studies also link extreme heat with higher rates of Escherichia coli in Italy and bacillary dysentery in China. In addition, the heat is affecting maize yields in Tanzania, potentially affecting the growth and nutrition of children.
School performance and outdoor activities
Extreme heat affects outdoor activities and can lead to injuries, especially among children and athletes. Agricultural workers, including children, often suffer from heat-related illnesses such as dizziness and headaches due to inadequate protection.
Student athletes are at increased risk of heat illness from physical exertion because many schools are not adequately prepared. Children play less in the heat, but shaded areas can encourage more activity. Heat waves also increase the number of unintentional injuries, especially among older adults.
Heat affects students’ well-being and performance at school. Air conditioning and better building materials are recommended to improve conditions.
Imbalances in impact
The health impacts of extreme heat are not evenly distributed across the population. Children from low-income families and members of ethnic minorities are at higher risk of adverse health effects during heatwaves.
The research found that these groups have higher rates of emergency room visits, low birth weights and premature births compared to their wealthier or white peers. The study also pointed to inequalities between generations: younger generations are expected to experience far more heatwaves in their lifetime than those born in earlier decades.
Conclusions
This review highlights the urgent need for targeted adaptation actions to protect vulnerable populations, especially children, from the health risks of extreme heat. Understanding and addressing inequalities in heat-related health outcomes will be critical to protecting public health as global temperatures continue to rise.
Children, especially newborns, are particularly vulnerable to extreme heat, which can lead to health problems such as premature births, stillbirths, low birth weight and heat-related illnesses. Children from socially disadvantaged families are at even greater risk during heatwaves.
To mitigate these impacts, the study suggests strategies such as creating greener playgrounds, implementing heat warning systems and adapting school environments to heat stress. Pediatricians are encouraged to counsel families on how to protect themselves during heatwaves, including staying hydrated and recognizing heat illness symptoms.
However, the report also highlights limitations, such as a lack of studies from developing countries and insufficient research on effective adaptation strategies. Future research should focus on these gaps to better protect children as global temperatures continue to rise.
Journal reference:
- Impacts of extreme heat and heat waves on child health: a scoping review. Schapiro, LH, McShane, MA, Marwah, HK, Callaghan, ME, Neudecker, ML DOI: 10.1016/j.joclim.2024.100335, https://www.sciencedirect.com/science/article/pii/S2667278224000385