The Norfolk-based gang targeted hospitals in County Durham, Stockport and Manchester between March 21 and 23.
Oliver Zak Henry Evans, 22, of Sandy Lane North, Wallington; Harry David Bradley Goodrum, 23, of Norwich Road, Dereham; Jake Alexander Roberts, 23, of Chestnut Hill, Norwich and Wayne John Grady, 41, of no fixed address, appeared at Teesside Crown Court today.
The four men all admitted a single charge of conspiracy to commit burglary at a previous hearing.
The men first broke in to Stepping Hill Hospital, in Stockport, and stole two nitrous oxide canisters, used for pain relief.
They then drove to Withington Hospital, in Manchester, and took another eight – some containing “gas and air” often used in childbirth and others nitrous oxide – from a storage unit.
They then travelled to the North East and smashed their way into a storage unit at Chester-le-Street Community Hospital to steal more canisters in the early hours of the next day.
Similar thefts were also committed at Bishop Auckland Hospital and Darlington Memorial Hospital, where the gang took 14 canisters from the latter, and drove off with them in the back of a BMW fitted with stolen number plates.
Police at Lincolnshire Police stopped a van the gang were using at a service station and found 29 gas canisters in the back.
Two of the men were arrested in the van, while the other two were stopped by North Yorkshire Police in the BMW.
They were each handed four years in prison by Recorder of Middlesbrough Judge Paul Watson QC at court today.
Detective Constable Helen Hudson, from Durham Constabulary, said: “This was an absolutely despicable crime.
“They deliberately targeted hospitals at a time when they were under enormous pressure because of the ongoing pandemic.
“These men showed complete disregard for anyone else when they removed these cannisters from the hospitals.
“Their actions could have posed a huge risk to the health and wellbeing of a significant number of people at a time when medical attention was needed.
“Hopefully this sentence will give these men the opportunity to think about their actions.”
“We would like to thank our colleagues at North Yorkshire, Lincolnshire and Greater Manchester Police for their help and support with bringing these criminals to justice.”