My parents attended a lecture on the history of Edinburgh (Scotland), and learned that (like many European cities) plague ravaged Edinburgh in the 16th and 17th centuries. At one point, Edinburgh asked people to stay inside and to hang a sheet on the door if they had the plague, so the plague doctor would know to visit their house. But the doctor died of (what else?) plague. So the city advertised for a replacement plague doctor, offering a lot of money for anyone willing to accept the role. One man did, and before stepping into homes designed a special leather suit with a breathing mask (a long beak stuffed with cotton with air holes at the end) to wear while treating patients. The doctor survived, and eventuallly the plague abated. But the city of Edinburgh was unable to pay, since they had expected the doctor to die of the plague so had not set money aside. The doctor never did receive his money.
Source: Lisa Didier, History of Edinburgh Scotland (lecture), 2016