The biggest ramification of climate change may not be storms or floods but more people dying from heat, with poorer and hottest regions set to suffer the most, a new report has warned.

While cooler areas may see fewer deaths, hotter countries and cities will face rising mortality if no action is taken, according to the Climate Impact Lab Mortality Report.

Cooler regions such as Scandinavia may actually see fewer temperature-related deaths drop by more than 70 per 100,000 people, because winters will be less deadly, while hotter regions such as Northern Africa, the Middle East, and Southwest Asia may see more heat-related deaths.

For example, the Sahel region, including Niger and Burkina Faso, may see an increase of more than 60 deaths per 100,000, higher than Africa’s current malaria death rate. In Pakistan, heat could cause an additional 51 deaths per 100,000 people by 2050, according to the report.