In the midst of last month's unwelcome arctic blast, animal-control officer Danny Rivera responded to South Philadelphia, where a dog had been left outside with no protection from temperatures that were expected to drop into the 20s.
Another officer from the nonprofit Animal Care and Control Team of Philadelphia had visited the home on Titan Street three days earlier. Rivera was returning to make sure the dog was indoors.
A woman led Rivera down into the basement to show that her tan-and-white pit bull was sheltered against the elements and appeared healthy.
"All that matters," Rivera told the woman, "is the dog is not out in the cold."
Recent bone-chilling temperatures served as a vivid reminder of last winter's frigid grip on the region and an early wake-up call for people involved with pet welfare in Philadelphia.
In June, Mayor Nutter signed into law an ordinance, introduced by City Councilman Kenyatta Johnson, designed to ensure that dogs were safeguarded against extreme weather.
The ordinance dovetails with the city's existing "code blue" system for helping homeless people in times of dangerous cold.
The city declares a code blue when the combined temperature and wind chill - or "real feel" - drops to about 20 degrees. The city can declare a "code gray" when higher temperatures are accompanied by high wind and heavy or frozen precipitation.
Now during a code blue, a dog must be brought indoors unless there is a suitable doghouse or structure to shield the pet.
The ordinance also kicks in for "code red" during a heat wave, which is defined as three consecutive days of 90 degrees or above. An owner would be required to ensure that the dog had appropriate shade from the sun.
Cats are not included in the ordinance, though owners are strongly urged to protect their pets from the weather.
ACCT Philly's primary job is to collect strays and unwanted pets for the city. The Pennsylvania SPCA, a separate nonprofit, investigates animal cruelty and neglect cases and, under state law, handled past cases of dogs left out in extreme cold.
ACCT will enforce the new regulations, however, because the law comes from the city, not the state.
"In the past, we would forward a call to the PSPCA," said Susan Cosby-Jennings, ACCT Philly's executive director. "But now with the city ordinance, we can do something with these calls."
Other organizations also respond to pets in need no matter the weather, such as Red Paw Emergency Relief Team, which aids pets and their owners who are displaced by fires.
What they may face now that winter has begun was summed up recently by Lori Albright, president and chief operating officer of Red Paw.
She recalled a night in January when she responded to a gas explosion near 18th and Bancroft Streets in South Philadelphia.
"It was so cold that the firefighters were struggling to open frozen hydrants," Albright said. "Utility workers couldn't break the frozen pavement with their tools to cap off gas lines."
Scores of residents and their pets were evacuated, but one man and his dog stood out: Nick and his 4-year-old boxer, Argyle.
When the explosion rocked the neighborhood, Nick, wearing only a T-shirt, pants, and socks, grabbed Argyle and ran outside to his car, where he put his dog.
Albright gave Nick a sweatshirt and more socks, then went with him to his car to retrieve Argyle.
"We literally walked through frozen puddles and ice for a half a block, which seemed like a mile," she said, "and [he] still had no shoes."
Albright took Nick and Argyle to her response vehicle, where the refugees huddled with the heat turned on while Albright tried to find someone who could recover Nick's wallet and phone.
With a hand-drawn map of Nick's bedroom, a city building inspector found Nick's wallet and phone - and grabbed a pair of boots.
Nick was then able to call his family, Albright said, "and stay with them for the night in a safe and warm house."