A record-breaking heatwave that has already caused large wildfires in western US states is set to continue next week.

Around 130m people were under some form of heat warning or advisory on Saturday. Nearly 57m people remain under heat alerts, as at least one child has already died in heat-related circumstances in Arizona.

Meteorologists are warning that warm nights will lead to people suffering heat stress. Temperatures could reach 128F (53C) in Death Valley on Monday.

While it is hard to link individual heatwaves to climate change, scientists say they are becoming more common and intense because of it.