This story was originally published on Oct. 10, 2019 in NYT Parenting.

It was 1 a.m. on Thursday, and Kristen Mascia was pumping breast milk in her car for her 2-month-old son.

The winds had finally picked up near her home in Kensington, Calif., between Berkeley and El Cerrito, and the power had cut out late Wednesday night, leaving her little choice but to retreat to her Mitsubishi hybrid. Fortunately, it had a standard outlet inside.

The Medela pump Ms. Mascia uses “is basically now an extension of my body,” she said. She pumps overnight to maintain a breast milk supply for her son, born six weeks early. “He and I are still establishing an exclusive nursing relationship,” she said.

[Read our guide on how to breastfeed during the first two weeks of life.]

Ms. Mascia, 36, was among around 600,000 electricity customers who were without power on Thursday morning after California’s largest utility, Pacific Gas and Electric, shut down electrical lines to try to prevent wildfires in Northern California. It was unclear how long the outage would last, but the company has said it could take up to five days to inspect the power lines and restore service.