The Beijing Meteorological Bureau released the first high temperature warning of this summer on Saturday.
In the next two to three days, the mercury will soar and temperatures will be above 35 degrees centigrade.
According to the Beijing Meteorological Bureau, the highest temperature in downtown area on Sunday was in Haidian district, where it was 39.5 centigrade.
"The hot muggy weather will last until Tuesday. We have published a notice to warn the public of heat stroke," Duan Li, a weather expert, told METRO on Sunday.
"We advise people to go out in the morning to avoid sunstroke, especially the old and children, who are more susceptible."
Confronted with the severe heat, Beijing Qianhe Senior Care Center is on alert to protect the senior citizens living there, according to the center's staff.
"The older people now tend to participate in outdoor activities in the shade or during the cooler evening. Nursing assistants will switch on air conditioners more often," said Huang Aiju, assistant to the dean of the center.
Other Beijingers looked to beat the heat by going for a swim.
"The number of guests was nearly 2,000 on Saturday, 400 more than last Saturday," said a receptionist at Yingdong swimming pool.
"Many parents brought their children here after lunch. We are having the busiest weekend since the beginning of summer."
The Beijing Bus Group has also assigned workers to assist help out at busy bus stations.
"Our transportation is in good condition. We have started our pre-program to ensure the safety and comfort of passengers," said Nan Tao, a press officer with Beijing Bus.
"The sun is so strong that my skin was burnt to a crisp. I don't want to go out, don't want to work and even don't want to eat. Everyone is less patient and getting more angry at others," said a passerby named Cao Ning near Beijing West Railway Station.
Cao said all she wants now is a rainy day.