A Colorado man almost died after stepping out of a hot shower into a cold bathroom due to an extremely rare allergic reaction, according to a report.
His family found him lying on the floor covered in hives and struggling to breathe as he suffered anaphylaxis from his allergy to the cold, according to Live Science, which cited a report in The Journal of Emergency Medicine.
The 34-year-old – who moved from Micronesia, which has a tropical climate — had previously experienced hives as a reaction to the cold, but not anaphylaxis, the report said.
The cold causes the immune system to release chemicals called histamines, which trigger an inflammatory response, according to Live Science.
Paramedics treated him with epinephrine and oxygen before rushing him to a hospital, where he sweated profusely with hives covering his entire body.
He was diagnosed with cold urticaria, an allergic reaction of the skin after exposure to cold temps, including cold air or cold water.
People can also develop the symptoms after consuming cold food or drinks, according to Live Science.
The most common symptom is a red, itchy rash, but in more serious cases, people can develop anaphylaxis, which can cause their blood pressure to plunge and airways to narrow.
Doctors confirmed his diagnosis using an “ice cube test,” which involved placing an ice cube on his skin for several minutes to see if he’d develop a red bump where the ice was.
The man, who was treated with antihistamine and steroids, was told to avoid exposure to cold water and also was prescribed an epinephrine auto-injector for emergencies.