Private equity put a unique stamp on these businesses. Unlike other for-profit companies, which often have years of experience making a product or offering a service, private equity’s primary expertise is in making money. And in many of these businesses, The Times found, private equity firms applied a sophisticated moneymaking playbook: a mix of cost cuts, price increases, lobbying and litigation.

In emergency care and firefighting, this approach creates a fundamental tension: the push to turn a profit while caring for people in their most vulnerable moments.