Researchers claim that keeping windows open on hospital wards could significantly reduce the risk of infections such as MRSA and C.difficile from spreading.
A study by the University of Leeds found that the trend of closing windows to cut heating bills could be increasing the risk of infection fourfold.
And in partitioning off parts of wards in order to meet same-sex accommodation regulations and increase patient privacy, hospitals have also changed the air-flow dynamics within these environments.
We found was that when the windows are open, these wards are very good, but if you close the windows and don't provide any alternative ventilation, the risks go up, and they go up about fourfold
The link was discovered through the use of computer modelling and smoke sticks to track the passage of air, wind streams and germs through traditional hospital wards.
The results suggest that keeping windows open would ensure good ventilation and cut down on the spread of bugs.
"One of the biggest problems we have in the UK at the moment is that we don't have the money to just knock down every hospital and rebuild it," said Dr Cath Noakes, who led the study.
"We have to deal with what we've got, and many of the wards we've got are going to remain in use for a number of years to come.
"Our research was looking at these big naturally-ventilated spaces to see what the risk of infection might be in there. What we found was that when the windows are open, these wards are very good, but if you close the windows and don't provide any alternative ventilation, the risks go up, and they go up about fourfold.
"People are being told to seal up their buildings to save energy, but we found that if you do that without alternative ventilation systems, you could be increasing the airborne infection risk significantly."
People are being told to seal up their buildings to save energy, but we found that if you do that without alternative ventilation systems, you could be increasing the airborne infection risk significantly
The research also looked at what could be done to maintain ventilation in the winter months when windows have to be kept closed to keep patients warm.
They found that fitting household extractor fans to windows would maintain sufficient air flow throughout these colder months.
Dr Noakes said: "We actually used the little extractor fans - the type of thing you get in your bathroom at home. We installed those into the window and when we ran them we found the risks became comparable to a naturally-ventilated system."
Co author, Dr Miller Camargo-Valero, added: "These simple, low-energy and low-cost solutions could also be of significant benefit for hospitals in the developing world, particularly in countries where airborne diseases such as tuberculosis are a major concern."