Schoolchildren in North Rhine-Westphalia (NRW) returned to the classroom on Wednesday after a six-and-a-half week break. New measures are in place, including mandatory face masks for secondary school students in order to prevent coronavirus outbreaks.

Germany's most populous state is the sixth to return to school after the summer vacation, but the only one to make the wearing of masks compulsory.

"We must be especially cautious during these times," said NRW State Premier Armin Laschet

Read more: Risks as Germany reopens schools in coronavirus pandemic

The reopening comes as Germany's infection rates are on the rise once more. The Robert Koch Institute for infectious diseases reported 1,226 new cases on Wednesday, the highest daily increase since May.

Last week, two schools in the state of Mecklenburg-Western Pomerania were closed after a fresh outbreak.

How schools are minimizing the risk

While class sizes are to remain the same, pupils and teachers NRW must wear a face mask at all times — including during lessons and break times.

Only primary school pupils are exempt from this rule. Teachers will be able to remove their masks if they are 1.5 meters away from the students.

Face masks will have to be worn in schools at least until the end of August.

School starts have been staggered to ensure that all children are not traveling at the same time. 

An additional 1,000 school buses have been made available across the state to ensure social distancing.

Students return during heatwave

Temperatures in NRW have continuously exceeded over 30 degrees Celsius this week, hampering the state's efforts to get schools completely back to normal.

High school pupils will now be exempted from lessons as soon as the temperatures in classrooms exceed 27 degrees Celsius.

Children with pre-existing conditions may be allowed to take part in "distance learning" from home.