Can Body Temperature Affect Your Breath Test Results?

Washington State DUI laws provide that the test of a DUI suspect’s alcohol level will be done by taking a sample of breath, and generally not blood.  However, breath alcohol content and blood alcohol content can be different, especially when a person’s body temperature is elevated.

When one drinks, the alcohol is absorbed by the body and eventually gets into the bloodstream. That same alcohol gets into the breath of a person through the interaction of the lungs and the bloodstream. It is a well known fact, however, that body temperature affects how much alcohol is passed from the blood to the breath. For instance, if a DUI suspect drank enough beer to produce a  blood alcohol reading of .07 (under the legal limit) you would think that the breath alcohol reading would be .07 as well. If the subject had a fever, however, the breath alcohol reading would be higher, perhaps over the .08 legal limit. This is not a theory but it is a scientific fact.

A study by G.R. Fox and J. S. Hayward published in 1989 in the Journal of Forsensic Sciences investigated whether breath testing inaccuracy would result if a subject’s body temperature was raised by spending some quality time in a hot tub. The study concluded that an elevated body temperature after hot tubbing did result in breath test readings that were significantly higher than blood tests taken at the same time.  The study recommended that breath testing machines be equipped with a device to monitor the temperature of the breath of a DUI suspect when blowing into an evidential breath testing machine such as the Datamaster.

Has anyone hot tubbed their way into a DUI arrest and conviction in Washington State who would have been innocent had they not elevated their body temperature? We will never know because the breath test machines used in Washington State for DUI convictions do not measure breath temperature and DUI officers are not required to take the subject’s temperature before administering a breath test.

If you are stopped for DUI and had a fever at the time you were stopped, make sure you let your attorney know. I could affect the outcome of your case.

Talk To A Knowledgeable Defense Attorney Before Making Any Decisions

Fury Duarte serves clients in the Seattle area and throughout Washington. We welcome the opportunity to discuss your case, and we encourage you to contact us for a complimentary consultation. You can reach our office in Bellevue by calling 425-643-1606.