Giant pandas Chu Xin (R) and Mu Yun stay at the panda hall of Siberian Tiger Park in Changchun, northeast China's Jilin Province, July 23, 2019. To give giant pandas a comfortable summer, zoo authorities have adjusted their diets and built an additional resting place and pond, which help them fend off the summer heatwave. (Xinhua/Lin Hong)

Giant panda Chu Xin eats bamboo at the panda hall of Siberian Tiger Park in Changchun, northeast China's Jilin Province, July 23, 2019. To give giant pandas a comfortable summer, zoo authorities have adjusted their diets and built an additional resting place and pond, which help them fend off the summer heatwave. (Xinhua/Lin Hong)

Giant panda Chu Xin eats bamboo at the panda hall of Siberian Tiger Park in Changchun, northeast China's Jilin Province, July 23, 2019. To give giant pandas a comfortable summer, zoo authorities have adjusted their diets and built an additional resting place and pond, which help them fend off the summer heatwave. (Xinhua/Lin Hong)

Giant panda Mu Yun eats bamboo at the panda hall of Siberian Tiger Park in Changchun, northeast China's Jilin Province, July 23, 2019. To give giant pandas a comfortable summer, zoo authorities have adjusted their diets and built an additional resting place and pond, which help them fend off the summer heatwave. (Xinhua/Lin Hong)

Giant panda Mu Yun drinks water at the panda hall of Siberian Tiger Park in Changchun, northeast China's Jilin Province, July 23, 2019. To give giant pandas a comfortable summer, zoo authorities have adjusted their diets and built an additional resting place and pond, which help them fend off the summer heatwave. (Xinhua/Lin Hong)

Giant panda Chu Xin rests on a tree trunk at the panda hall of Siberian Tiger Park in Changchun, northeast China's Jilin Province, July 23, 2019. To give giant pandas a comfortable summer, zoo authorities have adjusted their diets and built an additional resting place and pond, which help them fend off the summer heatwave. (Xinhua/Lin Hong)

Giant panda Chu Xin rests on a tree trunk at the panda hall of Siberian Tiger Park in Changchun, northeast China's Jilin Province, July 23, 2019. To give giant pandas a comfortable summer, zoo authorities have adjusted their diets and built an additional resting place and pond, which help them fend off the summer heatwave. (Xinhua/Lin Hong)

Giant panda Mu Yun eats bamboo at the panda hall of Siberian Tiger Park in Changchun, northeast China's Jilin Province, July 23, 2019. To give giant pandas a comfortable summer, zoo authorities have adjusted their diets and built an additional resting place and pond, which help them fend off the summer heatwave. (Xinhua/Lin Hong)

Giant panda Mu Yun eats bamboo at the panda hall of Siberian Tiger Park in Changchun, northeast China's Jilin Province, July 23, 2019. To give giant pandas a comfortable summer, zoo authorities have adjusted their diets and built an additional resting place and pond, which help them fend off the summer heatwave. (Xinhua/Lin Hong)