How Can Changing Body Temperature Impact BAC Levels in a DUI Case?
In Michigan, DataMaster operators are not trained much on body temperature and its impact on alcohol in the blood. In the human body, blood that is flowing in the capillaries of the lungs passes quite rapidly through the walls of the capillaries and alveoli into the deep lung air. The equilibrium formed is in the ratio of 1:2100—the same weight of alcohol is present in one milliliter of blood as in 2100 cubic centimeters of air.
The validity of this ratio depends on temperature, which for all persons is assumed to be 98.6˚ F (37˚ C) at the time of the test. The operators are not taught that the ratio 1:2100 represents an average value and that variations between individuals (body temperature among other things) are not considered sufficient to jeopardize the breath test results. The machine also assumes that everyone's body temperature is 93.2 degrees when it leaves the mouth into the machine.
The DataMaster in Michigan assumes that everyone's body temperature is always 98.6 F, and applying common sense, this is not always true. If the body's temperature is not at this level, the DataMaster is not accurate. Further, the machine does not collect 2100 cc of air, but only 52.5 cc of heated air and thus is only approximately 1/40th of the usual sample size.
So you're getting a result on the DataMaster that is not only subject to changes in body temperature, but also basing a reading off of 1/40th of the usual sample. This is like saying all 40 people like pizza, and only asking one person if they like pizza.
DataMaster operators in Michigan are not taught that if a person has a higher than normal body temperature, the result is artificially higher than it should be.
They are not taught that if a person has a higher than normal body temperature, the concentration of alcohol in the alveolar air will be increased. As a result, the DataMaster reading will be higher than it should be. You could have a blood result reading of 0.10, but in reality the number is significantly lower, which is the difference between under and over the legal limit.
If you've been charged with a DUI and your BAC level is close to the legal limit, you may have a possible defense based on your body temperature not being "average" when the test was given. I look forward to discussing the merits of this type of defense in greater detail.