Last Updated on July 2, 2025
Many things can cause a falsely high breathalyzer result, including diabetes or a low-carb diet. But did you know that even fevers can affect breathalyzers enough to result in your being charged and convicted of drunk driving? It’s true, and because being sick can cause you to drive poorly, your chances of getting pulled over are far greater when you are under the weather. It is vital to write down every detail of your DUI arrest as soon as you are released. A small detail like this can make all the difference when fighting a drunk driving conviction with the help of your lawyer.
How Fevers Can Affect Breathalyzers
So, how big of a difference can a temperature have on your breathalyzer results? Well, several studies on the subject have shown that fevers can affect breathalyzers with even a one-degree centigrade change in body temperature (about a 1.8-degree change in Fahrenheit), changing a breathalyzer test result by anywhere from 6.5% to 9%.
That can easily push what would normally be a BAC of 0.07% over the legal limit of 0.08%. This increase in BAC is even more problematic for minors, as a juvenile can get a DUI for having a BAC of even 0.01%. If you had even a mild fever when you took a breathalyzer test, this could be critical information to your attorney.
Cold Medicines Often Contain Alcohol
The BAC increase from a fever is particularly significant when you consider that many cold remedies contain alcohol -some up to 25%. If you are a smaller-sized individual and you took a cold medication to treat your symptoms, you could even be charged with a DUI without ever having consumed an alcoholic drink. You’re also more likely to be affected by the alcohol in cold medicine while sick because most people tend to eat less while they’re not feeling well, which means you will absorb the alochol more quickly and absorb more of it overall.
Even if your medication doesn’t contain alcohol, many can still negatively impact your ability to drive. Remember that you can still get a DUI for taking cold or flu medicines that affect your driving ability, even if your BAC is 0.00%.
You’re More Likely to Get Pulled Over When Sick
Just like operating a vehicle with a migraine, driving while sick can be dangerous even without taking cold medications. One study found that driving with a cold affects your ability to safely operate a vehicle as much as 8 shots of whiskey. Sick drivers have slower reaction times, break more suddenly and frequently, pay less attention to other cars, and drive more erratically. Symptoms such as sneezing and coughing can cause you to shake, force you to close your eyes, and may cause your eyes to water. A high temperature can make someone delirious or cause seizures, either of which could easily cause a car accident.
Fevers Aren’t the Only Reason for Body Temperature Changes
Of course, while fevers are the most common reason a person’s body temperature has risen, they are not the only reason. If you were in a hot tub, exercised vigorously, or were in the hot sun before you were given a breathalyzer test, be sure to tell your lawyer, as it may affect your case. On the upside, people in these situations are less likely to suffer negative symptoms related to illness, and the body’s temperature will usually go down again in a fairly reasonable amount of time.
If you have been charged with drunk driving, remember that every detail can be crucial, especially if you were feeling unwell. When you hire DUI lawyer Peter M. Liss, he will look at all potential defenses to your case to help you get the best possible outcome. If you have any questions or would like to schedule a free initial consultation, please call (760) 643-4050.
