Washington is warning Americans about the likely effects of a government shutdown should lawmakers fail to strike a deal to fund the government before it runs out of money Oct. 1 — from immediate furloughs for thousands of federal workers and cutbacks in veterans’ care to possible, longer-term national security risks.

The warnings are part of a 19-page advisory from Capitol Hill that makes clear federal agencies must cease operations under the so-called Antideficiency Act — except in emergency and other extreme situations.

And while federal programs and agencies that directly perform national security functions have historically been exempt, the advisory states that closing parts of the federal government indirectly related to the national “security apparatus … could result in increase risked to the nation.”

The advisory suggests that shuttered emergency services and support operations would delay the United States in recovering from a crisis or emergency.