The day they found Lee Odgers, it was so hot that the wax candles inside her Northeast Philadelphia apartment had started to melt.
The 87-year-old woman had been dead for hours, too long for investigators to get an accurate reading of her body temperature at the time of her death. They could not list hyperthermia -- an abnormally high temperature -- as the cause of death.
Yet the city was in the grip of an 11-day stretch with temperatures in the 90s that month, July 1993, and Odgers lived alone on the second floor of a red-brick rowhouse -- a staple of the Philadelphia streetscape that retains heat with dangerous efficiency. She had no air conditioning and her windows were closed.
Then-medical examiner Haresh Mirchandani decided that a broader recognition of heat's deadly impact was in order. The deaths of Odgers and 100 others that month would be classified as "heat-related."
Call him a prophet for the climate change era.
Philadelphia ramped up its heat-emergency response program that summer, extending hours for air-conditioned public facilities and swimming pools, assigning block captains to check on older, vulnerable residents, even asking utility companies to delay shutoffs for unpaid accounts. The city has prevented an average of 45 heat-related deaths a year since then, Brown University researchers estimated in a 2018 study.
But with the continued rise in temperatures, the challenge becomes more daunting by the year.
Between 1950 and 1999, the city saw an average of three days a year when temperatures exceeded 95 degrees. By the end of this century, temperatures could cross that sweltering threshold on 17 to 52 days a year, according to a 2015 report from the Mayor's Office of Sustainability, using models from the World Climate Research Programme. The wide range in that projection depends on how much governments rein in emissions of carbon dioxide and other heat-trapping greenhouse gases.
For those whose health already is compromised -- such as the old and frail who lack air conditioning, and people with heart or kidney disease -- physicians say this hotter future will be dangerous.
Extreme heat can kill in a variety of ways. Older people's blood vessels are less able to dilate in order to dissipate heat, adding strain on the heart. They also are more prone to dehydration and loss of vital electrolytes, raising the risk of kidney failure and irregular heartbeat -- especially for those whose organs already are compromised. People with weaker lungs struggle to breathe, as heat contributes to the formation of ground-level ozone, the main component of smog.