Nearly half a billion children are growing up in parts of the world that experience at least twice as many extremely hot days each year as they did 60 years ago, a Unicef ​​analysis found.

The UN Children’s Fund’s analysis was the first to examine data on changes in children’s exposure to extreme heat over the past 60 years.

As the planet continues to warm, people around the world are facing more frequent and severe climate threats, such as extreme heat and heat waves. Children are particularly vulnerable to such dangers.

To assess the rate and extent at which extremely hot days – defined as days with temperatures above 35 degrees Celsius (95 degrees Fahrenheit) – are increasing, researchers compared a temperature average from the 1960s with that from 2020 to 2024.

They found that 466 million children – about one in five children worldwide – live in areas where there are at least twice as many extremely hot days each year as there were 60 years ago.

They also found that children in West and Central Africa are exposed to the greatest heat and that this region has seen the largest increases over time.

A total of 123 million children, or 39 percent of children in the region, are exposed to temperatures above 35 degrees Celsius for an average of four months each year, according to the analysis.

The figures include 212 days in Mali, 202 days in Niger, 198 days in Senegal and 195 days in Sudan.

David Knaute, UNICEF’s climate expert for West and Central Africa, said: “This new UNICEF analysis is a stark warning of the speed and scale with which extremely hot days are affecting children. It urges governments to seize this precious opportunity to act and bring temperature rise under control.”

Extreme heat can lead to heat stress, which is a threat to children’s health. Heat stress is linked to malnutrition and non-communicable diseases in children and makes children more vulnerable to infectious diseases such as malaria and dengue fever, which spread in high temperatures.

According to Knaute, children are “particularly at risk” in extreme heat. “Unlike adults, their bodies heat up more quickly, they sweat less efficiently and cool down more slowly. If their small bodies cannot regulate heat, this leads to heat stress and they are more likely to suffer heat stroke or die.”

Last year was by far the warmest year on record, and scientists expect global temperatures to rise even further above pre-industrial levels, with devastating consequences for humanity and the planet.

The Unicef ​​analysis found that children in eight countries, including Mali, Niger, Senegal, Sudan and South Sudan, are exposed to temperatures above 35 degrees Celsius for more than half the year. Earlier this year, Mali experienced a record heatwave with temperatures reaching up to 44 degrees Celsius.

According to Knaute, the Sahel zone, the region south of the Sahara, which includes Mali, Niger, Senegal and Sudan, is particularly at risk. As a transition zone between the dry Sahara and the more fertile belt south of the desert, it is a natural source of strong warming, and dust particles from the desert disrupt the climate.

The lack of access to climate-resilient infrastructure, drinking water and adequate health care is exacerbating the impact of extreme heat on children living there, he said.

In addition to the physiological effects, extreme heat also has other consequences for children, including disruption to school performance.

Shruti Agarwal, a senior adviser on climate change and sustainable business at Save the Children, said extreme heat is increasingly leading to school closures, affecting academic performance.

Earlier this year, South Sudan closed all schools in preparation for a 45-degree heatwave that was expected to last two weeks. “As the number of hot days increases, we will see children’s learning outcomes suffer, which in turn will impact human capital development,” Agarwal said.

In addition, there could also be indirect risks to children’s health if extreme heat leads to crop failures or rising food prices, thereby causing malnutrition among children.

To minimize the impact of extreme heat on children, health and education systems must be appropriately equipped and children must be actively involved in planning and implementation, Agarwal said.

Unicef ​​recommends that countries take climate action that respects children’s right to a clean, healthy and sustainable environment by reducing emissions and complying with climate agreements.

“There is still hope for the future, but we must act now. Later is too late,” said Knaute.