The heat wave that has been roasting much of the U.S. in recent days is just getting warmed up, with temperatures expected to soar to dangerous levels through the weekend.
Communities are preparing by offering buildings as cooling centers and asking residents to check in on family members and neighbors. Officials are also concerned about smog, which is exacerbated by the heat and makes it harder for certain people to breathe, including the very young, the elderly and people with asthma or lung diseases.
The National Weather Service estimates that more than 100 local heat records will fall on Saturday, though most won't be daily highs but record-high nightly lows.
Greg Carbin, forecast branch chief for the weather service's Weather Prediction Center, says the heat wave will likely be "short and searing."