After taking medicine for a runny nose or cough, most people won’t go out and operate heavy machinery. But just operating a car could cause trouble. Iowa Department of Transportation safety specialist Scott Falb says cold medications can impair your driving. Antihistamines and cold remedies often carry label warnings that they can cause drowsiness, and Falb says you should heed those warnings. The problem increases if you’re drinking, too. Falb says some medication can be as fatal as alcohol if you get behind the wheel. Studies show medications can impair your driving just as much as if you’re legally drunk. Falb says it’s easy to overlook the effects of over-the-counter medications so you should read the label on all medications and not use them if they’ll impair your ability to drive.