The UN Secretary-General’s Call to Action on Extreme Heat brings together the diverse expertise and perspectives of ten specialized UN entities (FAO, ILO, OCHA, UNDRR, UNEP, UNESCO, UN-Habitat, UNICEF, WHO, WMO) in a first-of-its-kind joint product, underscoring the multi-sectoral impacts of extreme heat. Earth is becoming hotter and more dangerous for everyone, everywhere. Billions of people around the world are wilting under increasingly severe heatwaves driven largely by a fossil-fuel charged, human-induced climate crisis. Extreme heat is tearing through economies, widening inequalities, undermining the Sustainable Development Goals, and killing people. The Call for Action calls for an urgent and concerted effort to enhance international cooperation to address extreme heat in four critical areas: Caring for the vulnerable – Protecting workers – Boosting resilience of economies and societies using data and science – Limiting temperature rise to 1.5°C by phasing out fossil fuels and scaling up investment in renewable energy.