Data reveals hidden divide in coping with heat waves

A new study tracking the movements of 1 billion mobile phone devices has exposed how wealth and age create a hidden divide in people's ability to withstand heat waves. Scientists analyzing data from record-breaking temperatures in 2023 found that common measures to protect people living in cities—such as issuing alerts or planting trees to increase shade—often fail to help the most vulnerable. It follows a World Meteorological Organization warning that the last three years are now officially the warmest on record.