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.

33-Year-Old Who Was Reported Missing From Naas Has Been Located
Kfm Obituary Notices
Talks Between Owners Of Derelict Robertstown Hotel And Council Regarding It's Future Use In Advanced Stages
Road Safety Talk Taking Place This Evening To Address Beggars End Junction Issues
Two Councillors Express Dismay Amid Ongoing Water Outages Following Low Levels In Allen Reservoir
Search Underway For Mountjoy Prisoner Who Walked Out Of Naas Courthouse On Friday
Allenwood Residents Advised Of Impacted Water Supply Until This Evening Due To Low Reservoir Levels