Managing Heat Waves: When Heat Becomes a Health Crisis

Heat has become one of the fastest growing health threats. In June 2026, the UK Met Office issued a red extreme heat warning — the highest level of warning issued when temperatures are life-threatening.

How heat harms health

High temperatures increase risks for the cardiovascular system, the elderly, infants, and people with chronic diseases. It also reduces labor productivity and puts pressure on healthcare systems. The most vulnerable are:

• Elderly and infants — reduced thermoregulation

• People with chronic diseases

• People employed in open spaces (agriculture, construction)

• Low-income communities — limited access to cooling

Latest data

According to the Lancet Countdown to 2025, heatwaves are expected to cause 640 billion working hours lost worldwide in 2024 (98% more than the 1990–1999 average), at a cost of $1.09 trillion—almost 1% of global gross domestic product. The burden is borne most heavily by less developed countries.

The disparity is clear: 48% of households in highly developed countries have air conditioning, while only 2% in less developed countries. In 2012–2021, heat-related deaths accounted for 1.7% of total deaths in less developed countries, compared to 0.5% in highly developed countries.

Solutions

Solutions to extreme heat often coincide with sustainable development steps:

• Greening cities — reducing the heat island effect

• Early warning and heat health action plans

• Energy-efficient and cooling apartment standards

• Protection of workers in open spaces — breaks, hydration

• Reducing fossil fuel emissions in the long term

Conclusion

The interplay between heat and climate change is not a distant threat, it is an ongoing health crisis that requires immediate and coordinated action at all levels.