Coronavirus guidance for teachers whose pupils have additional support needs (ASN) is "totally inadequate", a teachers' union has said.
The EIS union says ASN pupils need close support, and staff are often putting themselves at risk to meet their needs.
The union is calling for extra staffing and more detailed safety advice.
The Scottish government said funding was being provided for more staff.
The issue about the challenges faced by ASN teachers was raised at an online union meeting on Wednesday.
Afterwards the union shared some of the comments made by teachers from across Scotland.
One said they couldn't function in line with the guidance on coronavirus, adding: "The pupils we are working with need the close contact and the close support, which is totally incompatible with [the] guidance."
Another said they had to "struggle through", and were having to get "too close to pupils for prolonged periods of time".
The challenges of wearing PPE were also raised, with another teacher saying pupils couldn't always understand why staff were wearing masks.
Extra cleaning responsibilities were also falling to teachers, it was claimed.
"Advice on ASN [provision] was too late, too vague, and totally inadequate," another said.
Larry Flanagan of the EIS said it was "extremely clear that the current Covid guidance is totally inadequate", in particular for teachers working with those who have more complex additional support needs.
He added: "There is a desperate need for more detailed guidance and enhanced staffing to ensure that the needs of all young people with additional support needs, particularly the most complex can be met in a Covid-secure school environment."
Mr Flanagan also said ASN teachers were "potentially putting themselves at greater risk of being exposed to Covid".
"The current situation, with ASN teachers being compelled to clean classrooms, including cleaning up bodily fluids, in order to ensure a safe environment simply isn't sustainable," he added.
A spokesman for the Scottish government said local authorities were responsible for meeting pupils' additional support needs, including the provision of teachers and support staff.
An extra £15m would be invested this year to allow schools to respond to the individual needs of children. Funding of £50m has been ring-fenced to recruit about 850 extra teachers and 200 additional support staff to support education recovery, the spokesman added.
'Sensory overload' in larger class sizes
Five-year-old Liam's dad Mark Henry-Rowan has set up a petition calling for a review of additional support provision in schools, after Liam was sent home every day for 12 of the first 15 days of the new term.
Liam and other children like him are struggling to cope in classrooms and therefore losing out on their education, according to Mr Henry-Rowan.
When he raised his concerns with his school in Fife, it suggested cutting him down to half days.
But Mr Henry-Rowan said halving his son's education was unacceptable.
He would prefer for children like Liam to have more staff members to support each class.
Liam went back to school as part of a class that was originally six, but is now 10 pupils.
His father said the guidance issued by teaching unions is that classes should be a maximum of six for children with Liam's needs.
"When he's been put in [the class] it's caused a sensory overload which has caused him to meltdown... they've used it as an excuse to send him home to resolve the problem with class sizes," he told BBC Scotland.
Fife Council said staffing was reviewed annually and was within national guidelines.
It added: "We are confident that we are able to meet the range of children's needs with the current staffing levels".
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