INMO General Secretary says members are very concerned about health and safety measures in hospitals.
It comes as 217 Covid patients are now in hospital, which is four times higher than this day last month.
31 people are in ICU with the virus, but there are 381 patients across the country without beds who are waiting in wards and corridors for treatment.
"When you consider overcrowding at that level, in normal times it would be considered very serious. But during a pandemic, when we have an airborne infection, it's extremely dangerous," says INMO General Secretary Phil Ni Sheaghdha.
She continued: "Our members are telling us that they are working in environments that are not safe. They're very concerned about the normal health and safety measures, particularly airflow and ventilation."
Meanwhile, Covid-19 hospital numbers have not peaked yet, according to an official from the Irish Medical Organisation.
It comes after 1,837 new virus cases were confirmed yesterday.
Over the weekend, 9,000 people got their first dose vaccine at walk-in centre.
HSE CEO Paul Reid says we're now on the final leg of our rollout.
12-15 year olds will be able to register for their jab from Thursday.
