Hundreds of thousands of people in different parts of the US continue to be affected by power outages as temperatures soar to record highs.
Firefighters near San Diego battled a blaze in soaring temperatures
In California, where temperatures reached 50C (122F), the heat may have killed up to eight people.
The power grid was unable to cope with the increased demand for electricity, leading to widespread cuts.
In California, Missouri and New York thousands are still without power after high temperatures and storms last week.
Early Monday, firefighters battled a soaring blaze in the Cleveland National Forest near San Diego and hundreds of homes were evacuated.
In the dark
As some 100,000 power customers in California faced further blackouts, authorities in the state investigated up to eight possible heat-related deaths, including a nursing home patient.
Meanwhile, about 230,000 homes and businesses in St Louis, Missouri were still without power.
New York utility workers managed to restore electricity to 22, 000 customers, many of whom had spent the week without power.
Residents in New York City were without power for a week
More than 20 heat-related deaths were reported last week across the United States.
While temperatures have since cooled in some parts of the country, California is bracing itself for more hot weather this week.
Forecasters predicted on Monday high temperatures in central and Northern California of up to 44C (111F).
They say high temperatures will continue until at least mid-week, prompting fears that there may be more power outages as people return to work after the weekend.