00:58 Heat Turns Deadly in Maryland, Buckles Roads in Kansas As the heat cranks up, Maryland reports two more deaths. Northeast cities are preparing for blackouts, and in Kansas at least two roads have buckled.

At a Glance Heat-related illnesses killed two people in the past week in Maryland.

Large cracks opened in roads in Wichita, Kansas.

Extreme heat killed 108 people in 2018.

The heat wave covering much of the United States has killed two people in Maryland and caused roads to buckle in Kansas.

With temperatures expected to rise into the mid-90s or higher i n the central and eastern states, communities are opening public buildings as shelters and encouraging residents to check on relatives.

Two people — a man in Prince George's County and a woman in Worcester County — died of heat-related illnesses in the week ending Monday, according to the Maryland Department of Health. Altogether, four people have died of heat-related illnesses this month.

In Baltimore, where the heat index is forecast to reach more than 100 degrees, City Health Commissioner Letitia Dzirasa has issued a code red extreme heat alert through Sunday.

(MORE: Dangerous Heat Wave to Expand from Plains, Midwest to East This Week)

“Excessive heat is the leading weather-related killer in the United States. The effects of extreme heat are exacerbated in urban areas, especially when combined with high humidity and poor air quality,” Dzirasa said in a news release. “Extreme heat is particularly dangerous to young children, older adults, and those with chronic medical conditions. I encourage all residents to take the necessary steps to protect themselves as well as their families, neighbors, and pets.”

<img class="styles__noscript__2rw2y" src="https://s.w-x.co/util/image/w/ap19198789502647.jpg?v=at&w=485&h=273" srcset="https://s.w-x.co/util/image/w/ap19198789502647.jpg?v=at&w=485&h=273 400w, https://s.w-x.co/util/image/w/ap19198789502647.jpg?v=ap&w=980&h=551 800w" > Jaxon Claymore, 8, left, and his older brother Jalen, 9, battle each other with large water guns in the hot mid-day sun in front of their apartment building on Wednesday, July 17, 2019, Bismarck, N.D. The pair say they compete against one another at home and in school to see who is the best in sports from running, throwing and strength. The weather forecast for the area calls for temperatures in the 80s with little chance of rain for the next several days. (Mike McCleary/The Bismarck Tribune via AP)

Extreme heat has caused roads to buckle in Wichita, Kansas, where the temperature reached 100 degrees Wednesday, the Wichita Eagle reports.

Shara McMahon told KSNW she drove over a large crack on South Broadway.

“I was thinking, ‘oh my gosh, what in the world was that?'” McMahon said. I went over the bump and I lost my breath. It was pretty big. I had no idea it was even there.”

Police in Hays, Kansas, also reported cracked and buckled asphalt there.

(MORE: New York Could See More Blackouts as Sweltering Heat Wave Sets In)

“The buckling is essentially caused by concrete, which is more rigid than asphalt, expanding to the point it breaks open at a weak point during hot weather,” Tim Potter, a Kansas Department of Transportation spokesman, told the Eagle. “Sometimes, the pressure can cause concrete to explode into the air. The problem also can occur when asphalt is laid over concrete. The dark asphalt absorbs heat and can add to the pressure.”

In Wisconsin, at least three school districts canceled classes. The heat index is expected to reach 110 degrees Friday.

<img class="styles__noscript__2rw2y" src="https://s.w-x.co/util/image/w/ap19198732132807.jpg?v=at&w=485&h=273" srcset="https://s.w-x.co/util/image/w/ap19198732132807.jpg?v=at&w=485&h=273 400w, https://s.w-x.co/util/image/w/ap19198732132807.jpg?v=ap&w=980&h=551 800w" > Russ Wilson splashes water on his face from a fountain in New York, Wednesday, July 17, 2019. The heat wave that has been roasting much of the U.S. in recent days is just getting warmed up, with temperatures expected to soar to dangerous levels through the weekend. (AP Photo/Seth Wenig)

The emergency management agency in Indiana's Greene County has asked churches and other organizations to open their doors as possible lifesaving cooling centers, the Associated Press reported.

The police station and a fire station will remain open as a cooling shelter in Westland, a suburb of Detroit. Police in Orland Park, a Chicago suburb, will keep their station open as a 24-hour cooling center.

(MORE: Four Things Extreme Heat Does To Your Body)

Extreme heat killed 108 people in 2018 , more than any other weather event.

The Centers for Disease Control and Prevention offer these suggestions for staying safe during extreme heat:

Stay in air-conditioned buildings. If you don't have air conditioning, contact your health department or locate an air-conditioned shelter.

Drink more water than usual and don’t wait until you’re thirsty to drink.

Don’t use the stove or oven to cook.

Wear loose, lightweight, light-colored clothing.

Take cool showers or baths to cool down.

Do not engage in very strenuous activities and get plenty of rest.

Check on a friend or neighbor and have someone do the same for you.

Click here for additional tips to prevent heat-related illness.