Leading nurses warn that the Spice epidemic sweeping UK prisons is putting nursing staff at risk.
The Royal College of Nursing (RCN), which is holding its annual congress in Belfast, said that nurses and healthcare assistants are often first on the scene when inmates need emergency care.
The nursing union has called for action after it said that, under current guidance, nurses and healthcare assistant are expected to enter cells before the smoke has cleared.
But after dashing to the scene to help patients, one prison nurse has been taken to A&E by ambulance after being left unconscious by the psychoactive fumes.
Meanwhile others have reported being unable to drive after inhaling fumes while trying to treat patients.
One RCN member reported treating more than 50 cases in a week.
The union has written to Michael Spurr, chief executive of HM Prison and Probation Service, calling on prison bosses to do more to protect nurses and other health workers from the effects of the drug.
The RCN said that Tees, Esk & Wear Valley NHS Trust withdrew nursing staff from a wing of Holme House prison in County Durham due to the risk posed by Spice.
It said that the use of psychoactive substances has become "widespread" in British prisons.
Janet Davies, RCN general secretary, said: "Spice poses a serious threat to nurses, healthcare assistants and prison staff, whose safety and long-term health is being put at risk day in, day out. We would like to see an urgent review of the guidance that properly reflects the risks posed by this extremely dangerous drug."
A Prison Service spokesman said: "We look forward to discussing these issues with the Royal College of Nursing."
Meanwhile, nurses at the congress will also debate nurse training in relation to suicide.
Members will call for universities offering nursing degrees to include training on suicide prevention.
A previous survey by the college found that three in five nurses had not received any training in suicide prevention or awareness as part of their nursing degree.
Mental health nurse Tim Coupland said: "We all need the confidence to be able to talk frankly and openly with patients about how they are feeling, in order to let them know we can support and help them."