53． Many places in northern China including Beijing（1）
（sweep） by heatwaves since Thursday with temperatures in some areas exceeding 40°C，leading to alerts from observatory authorities for high temperatures and advice on avoiding outdoor activities.
The National Meteorological Center renewed a yellow alert on Friday morning for high temperatures.It has a three-tier，color-coded warning system for such high temperatures，with red being（2）
（severe） warning，followed by orange and yellow.
According to（3）
center's real-time temperature map at 2 pm on Friday，Beijing，Tianjin，most parts of Hebei and some neighboring areas were hit by the highest temperatures nationwide，which were all above 37°C.Beijing Meteorological Service（4）
（issue） an orange alert on Friday morning for the（5）
（expect） high temperatures from Friday to Saturday.
The observatory watchdog in Tianjin upgraded（6）
orange alert to red on Friday morning while neighboring Hebei province renewed its red alert.
Meteorological authorities in the places hit by heatwaves advised（7）
（local） to avoid outdoor activities during high-temperature periods in the afternoon and suggested that working units provide necessary protective measures for employees（8）
（avoid） heatstroke.
"We have suspended the work for two days at most of our construction sites，（9）
one or two are still under work for emergency，' ' said Wang Xu，a project manager at a construction company in Shijiazhuang，Hebei.Employees still at work have been provided（10）
protection，he added.
