Scorching triple-digit temperatures in Texas this week put the state in competition with the hottest places on the planet, including the Sahara desert and parts of the Persian Gulf.

Texas has been roasting for weeks under a severe early season heat wave that is now spreading to the Lower Mississippi Valley and parts of the Southeast.

Over the past week, several Texas cities, including San Angelo and Del Rio, have hit or exceeded 110 degrees Fahrenheit (43 degrees Celsius), temperatures that are more common this time of year in parts of North Africa and the Middle East.

The Texas Electric Reliability Board, the operator of the state’s power grid, said power use hit a preliminary all-time high Tuesday as demand for air conditioning soared. Reuters reported. ERCOT said it expects another record to be set on Wednesday.

A stagnant dome of high pressure has fueled dangerous heat and humidity across most of the state, and local officials are warning people to take precautions and limit time outdoors.

Extreme temperatures have already taken their toll. Data from the Centers for Disease Control and Prevention showed that the rate of emergency department visits attributed to heat last week was about 30% higher compared to the same period last year.

An average of 702 heat-related deaths occur each year in the United States, According to the Centers for Disease Control and Prevention. The National Weather Service has said that heat causes more deaths across the country each year than any other weather event, including tornadoes, floods and hurricanes.

Brutally hot conditions are expected to persist throughout Texas on Wednesday, with many places experiencing temperatures in the triple digits.

Meanwhile, about 87 million people in the Midwest and parts of the Northeast are at risk of poor air quality from smoke from the Canadian wildfires.

He The National Weather Service said in an update early Wednesday that the heat dome is expected to “spread north into the Middle Mississippi Valley” bringing high temperatures that won’t get much cooler overnight. Forecasters have said much of the South will likely experience extreme heat and humidity that will linger through the July 4 holiday.