BALTIMORE, MD (July 2, 2019) With a forecasted heat wave to grip the Baltimore region this week, and a heat index expected to reach 97 degrees Fahrenheit or higher for several days, Baltimore City Health Commissioner Dr. Letitia Dzirasa has issued a Code Red Extreme Heat Alert for tomorrow, Wednesday, July 3rd through Saturday, July 6th. The heat index is a measure of air temperature and relative humidity and indicates how hot it feels to the human body.