Farmer's fever, also called organic dust toxic syndrome (ODTS), is caused by breathing in dust which contains moulds from spoiled plant materials. It is a common respiratory illness in farmers, particularly those working with grain, hay, silage and confined animals. The symptoms are a fever and flu-like symptoms which occur four to 12 hours after exposure to contaminated dust.
The symptoms of farmer's fever usually disappear within one to three days after you are no longer exposed to the dust. ODTS is often misdiagnosed, so it is important to tell your doctor about any recent dust exposures you may have had.