The Fever Defense


I had the flu not too long ago. One of the worst parts of the flu was the fever that came with it. I’d throw blankets on because of the shivers only to throw them off because after a few minutes they’re soaked in sweat. And the cycle repeated. I took Dayquil, cough syrup, and a litany of other medicine, many of which could have caused be to be “under the influence” for purposes of a DUI.

That same fever could have also caused a breathalyzer reading that was above what it actually was.

Breathalyzers assume that all people are exactly the same; that no one has gastroesophageal reflux disease (GERD), no one is on a low carb diet, no one is hypoglycemic, and everyone has the same, average temperature of 98.6%. Obviously we are all different and unfortunately all of these differences can affect the accuracy of a breathalyzer including an elevated temperature.

There are numerous studies out there suggesting that an elevated temperature can cause an elevated reading on a breathalyzer. One such study published in the Journal of Forensic Sciences in 1989 tested exactly this. Subjects were given a breathalyzer and a blood test after sitting in a hot tub. The breathalyzer readings were significantly higher that the blood tests.

In the 1990 study “The Myth of Breath Test Accuracy, What the Studies Have Really Shown,” researchers concluded that one degree centigrade change in breath temperature can cause a change in blood alcohol content reading by 6.5 percent. Other studies have estimated the change to be as high as 9 percent. This could be the difference between a blood alcohol content reading of 0.07 percent and a 0.08 percent, which we all know is illegal to drive with.

Should I have driven while suffering from the flu and I had an actual blood alcohol content of 0.07 percent, it is possible that the fever could have caused a false-positive breathalyzer reading of 0.08 percent.

A fever is not the only cause of an elevated body temperature. Some people naturally have an elevated core body temperature. Some people enjoy hot tubs. Some people can get an elevated body temperature after sitting in the back of hot police vehicle or a hot police station.

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