More than a million people are still without power in seven states and the District of Columbia, and many are using generators that emit fumes that can be dangerous in enclosed spaces. Utilities warned that many neighborhoods could remain in the dark for much of the week, if not beyond.
Many of the deaths were caused by the severe wind storms, called a derecho, which swept from the Midwest to the mid-Atlantic late last week. In Maryland, eight people died from heat-related causes.
The extreme heat is expected to continue through the week.
Adding to the urgency of the repairs are the sick and elderly, who are especially vulnerable without air conditioning in the sweltering triple-digit heat. Many sought refuge in hotels or basements.
The Associated Press contributed to this report.