BALTIMORE, MD (July 15, 2019) With another heat wave brewing across the Baltimore region this week, and with the heat index forecasted to reach over 100 degrees Fahrenheit for several days, Baltimore City Health Commissioner Dr. Letitia Dzirasa has issued a Code Red Extreme Heat Alert for tomorrow, Tuesday, July 16th through Sunday, July 21st. The heat index is a measure of air temperature and relative humidity and indicates how hot it feels to the human body.