Climate change is already having severe impacts across our planet, bringing new and previously unimaginable challenges to the people least responsible for greenhouse gas emissions.

This report, the first we’ve released jointly in the history of our organizations, provides a sobering review of how just one of those challenges – the increase in deadly heat-waves – threatens to drive new emergency needs in the not-so-distant future.

The findings are startling and disturbing. Heatwaves already kill thousands of people every year, and they will become deadlier with every further increment of climate change. We hope this report serves not only as a wake-up call but also as a road map. Heatwaves demand a humanitarian response that is locally grounded, that acts quickly on the basis of data and analysis, and that works in partnerships with local governments, civil society and development actors to protect the most vulnerable people.

The challenge is daunting, but there is demonstrable success to build on, including from developing countries.

But even as we seek to improve our emergency response to extreme heat, let us be clear: This is not a problem that humanitarian organizations can solve alone. The urgent priority must be large and sustained investments that mitigate climate change and support long-term adaptation for the most vulnerable people. Without those investments, we are destined for a future of ever larger and deadlier heat disasters.


Devastating droughts like the ones pushing Somalia to the brink of famine are made far deadlier when they combine with extreme heat. We can expect more of these in the future. Indeed, things are only going to get far worse as climate change continues to spiral out of control.

The combined effects of warming, ageing and urbanization will cause a significant increase in the number of people at risk in developing countries on this phenomenon in the decades to come.

We are particularly concerned about the impact of these heat emergencies on people in the countries we support together and collectively providing humanitarian assistance and protection– including in Latin America, the Sahel, South and South-West Asia and the Horn of Africa. Because in heatwaves, it is the most vulnerable and marginalized people who will suffer – people who are already suffering from hunger, conflict and poverty.