Students self-isolating at the University of York have been told to wait in their room in the event of a fire and let others out first.
The university's Health and Safety Services told students to wait for a minute before leaving "to allow non-isolating individuals to exit".
In total 288 staff and students at the university have tested positive for coronavirus.
The university said it had since "updated and changed" its guidance.
However, it has not yet made it clear if the advice to self-isolating students is still applicable.
The instruction was sent out in a email to self-isolating students earlier this week.
It said the "additional guidance" had been developed to "maintain social-distancing from non-isolating residents".
The guidance stated: "If you are self isolating and the fire system in your accommodation building is activated please follow these procedures to ensure your safety.
"When the alarm sounds; stay in your room for one minute then make your way to the nearest refuge (this will allow non-isolating individuals to exit the building)."
Self-isolating students were then asked to contact the university's Security Services from a refuge area and wait to be told if they needed to evacuate the building.
North Yorkshire Fire and Rescue Service said officials had contacted the university after being made aware of the guidance.
A University of York spokesperson said: "Our advice and guidance has been updated and changed.
"We take the health and safety of our students and staff extremely seriously.
"All students are required to undertake a mandatory fire safety induction and this clearly states that all students should evacuate the building immediately, meeting at the designated fire assembly point.
"Students are reminded that in gathering at the fire assembly point, they should adhere to social distancing guidelines."