In the coming week, there are over 100 high temperature records that could be broken, mainly across the southern and eastern regions of the US.
Many areas expected to set records were also hit with extreme heat last week when a massive heat dome brought triple-digit temperatures to states across the eastern US and Midwest, breaking record daily highs in several cities.
This past weekend saw several new daily record high temperatures, including in New Orleans, which clocked a high of 97 degrees, and in Mobile, Alabama, which surpassed its 1913 record of 100 degrees when it inched up to 101 degrees on Saturday.
As of early Monday morning, more than nine million people were under heat alerts across eight states in the northern and central US, including Minnesota, Iowa, North Dakota, South Dakota, Michigan, Wisconsin, Nebraska and Kansas.
But this number is expected to increase throughout the week as the heat continues to build across the northern Plains, Midwest and Gulf Coast on Monday, potentially bringing triple-digit temperature records as it progresses into the Southeast and Mid-Atlantic on Tuesday.
Many communities battling the heat may not get much relief at night, either, as there are an additional 100 record high overnight low temperatures forecast to be broken throughout the week.
The continuing heat follows a week in which extreme weather struck millions of people across the US. In addition to the massive heat dome, historic flooding inundated Yellowstone National Park and its surrounding communities, wildfires blazed in Arizona and New Mexico, and severe storms in the upper Midwest and Ohio River Valley caused widespread power outages.
Hundreds of thousands of people, including about 180,000 in Ohio, had to endure excessive heat wave temperatures without electricity due to the outages.
Extremely high temperatures can lead to common heat-related conditions such as heatstroke and heat exhaustion, which occur when the body is unable to properly cool itself. It can also impose significant strain on the heart and make breathing more difficult.
Infants, children, the elderly and people with chronic illnesses or mental health problems are especially vulnerable to heat-related illnesses, though young and healthy people may be affected, too, if they are doing strenuous activity in excessive temperatures, according to the CDC.
While children do not die from heat-related illnesses as much as the elderly, a study published in January found that “climate shocks” like sweltering heat waves can cumulatively affect a child’s long-term health. Over time, such events may contribute to significantly higher rates of substance abuse and health problems like cancer and heart disease, researchers said.
As climate change drives temperatures higher, scientists expect heat to make even more people ill, especially because heatwaves are becoming more frequent.
In the 1960s, Americans saw an average of two heatwaves a year, but by the 2010s, the average increased to six per year, according to the EPA.
CNN’s Allison Chinchar, Jen Christensen and Rachel Ramirez contributed to this report.