The level-two emergency response covers provinces including east China's Anhui, Jiangsu, Zhejiang and Jiangxi, central China's Hunan and Hubei, south China's Fujian, and Shanghai and Chongqing municipalities.
The response was launched after a second-level heat alert was issued for two consecutive days and will continue for the following three days, state-run Xinhua news agency reported.
The second-level heat alert has lasted for four consecutive days, with the highest temperature in the country exceeding 37 degrees Celsius.
The CMA forecast that temperatures over 35 degrees Celsius will linger along the Yangtze River and the Huaihe River, regions south of the Yangtze River and southwest Chongqing Municipality from today to August 8.
Authorities have warned public against heatstroke and fires. They have also recommended people to take sufficient measures to stay cool and limit their outdoor activities.