The city’s brutal heat wave has claimed its first victim — a 94-year-old woman from Brooklyn, authorities said today.

The woman died Saturday from “hyperthermia due to exposure to high environmental temperature with underlying natural disease,” according to the Medical Examiner’s office. Officials did not release her name or address.

Temperatures on Saturday soared to record-setting 100, according to Accuweather.com. The day before, the mercury hit an unbearable 104 degrees.