Climate change threatens global health with deadly heatwaves, rising infectious diseases and failing hospitals. Each year, extreme heat kills more than 540,000 people. One in 12 hospitals faces the risk of closure due to climate change. Health systems are burdened by economic and political shocks and other pressures caused by climate change. People are being forced to leave their homes, food is harder to grow and there is a risk of new pandemics. These impacts hit low-income countries and the poorest people, who contribute the least to carbon emissions, the hardest. Inaction has already cost lives, and protecting against these risks is a legal, moral and economic obligation for countries. COP30 brought hope.