So far this year, nine people in Maryland have died from heat-related problems. The latest victims are a man in Prince George's county, a man in Somerset county and a woman in Baltimore.
While the elderly are more vulnerable to heat stroke, two of last week's victims were under the age of 65. All of them had underlying health problems.
Last week's record-setting temperatures caused the number of heat victims seeking treatment in Maryland emergency rooms to soar, from 43 on Wednesday to 115 on Friday, when temperatures reached their peak in most areas of the state.