The Department of Eduction has advised schools.
The Department of Education is advising schools that windows do not need to be wide open during cold and windy weather.
Many teachers have highlighted the low temperatures students are being expected to learn in, on social media today.
Schools have been previously advised to keep windows open, in order to reduce the spread of Covid- 19 in classrooms.
It's understood at least one school in Dublin sent students home due to the cold weather.
Kildare's Fianna Fail senator and former teacher Fiona O'Loughlin is currently volunteering as a substitute, she says opening windows after classes may be a better option.