Alternate care site

[9]: 1393  French surgeon-major Dominique Jean Larrey sought to improve on contemporary practice whereby wounded soldiers remained on the battlefield until they could be evacuated to distant centralized medical facilities.

[11]: 128–29  The experience with the Spanish flu pandemic highlighted the importance of planning for ACS setup before a crisis strikes: while buildings were easy to find, equipment and staff were in short supply, complicating the establishment of functioning ACSes.

[12]: 253  More recently, ACSes have been established in response to large-scale disasters, such as Hurricane Katrina, when the Dallas Convention Center was used for this purpose for its first time.

[6]: 3 An ACS that is no longer actively providing care, but remains outfitted to resume doing so on short notice is said to be in warm status.

[2]: 27 [16] In March 2020, as public-health authorities began to recognize the potential scope of the COVID-19 pandemic, an initial question was whether to use ACSes for those patients with the SARS-CoV-2 virus, or without it.

[4] While the intuitive answer initially appeared to be that ACSes should be for virus-free patients, several factors ultimately led to a consensus forming around using these facilities exclusively for patients with the virus; these factors included the unreliability of testing, the ability to conserve personal protective equipment and the ability for the facility to specialize in the care of COVID-19.

The Javits Center in New York City has been used as an ACS during the COVID-19 pandemic.
Suggested layout for an ACS in a hotel or other building with numerous rooms.
Suggested layout for an ACS in a building with a large open space, such as a convention center.
A patient treatment area within the Javits center while it was being used as an ACS during the early weeks of the COVID-19 pandemic.