U.S. Indo-Pacific Command on Tuesday raised the “health protection condition” level to “Charlie” for military members in Hawaii — indicating a “substantial risk of exposure” to coronavirus, U.S. Army Garrison Hawaii said.

The Army said it is reducing operating forces to “minimum essential personnel” effective today.

“Each commander will decide which personnel are necessary and required to carry out those units’ missions,” garrison commander Col. Tom Barrett said during a Facebook community briefing Tuesday evening. “Personnel who have been released must follow stay-in-place guidelines.”

Barrett said of the 90 positive COVID-19 cases reported by the state so far, five are within the U.S. Army Hawaii community.

At condition level Charlie, “the risk level is increasing, and it is beginning to be substantial, so we are seeing sustained community transmission in Hawaii,” Barrett said.

Defense Secretary Mark Esper on Tuesday discussed the challenges of maintaining coronavirus social distancing within a military that needs to train and operate in close proximity, saying, “You can’t get social distancing in a submarine or even in a tank, right?”

“But you take prudent measures as best you can, given the situation you’re in, given your mission … and that’s what we call upon commanders and senior (noncommissioned officers) at all levels to do: Assess their situation, and if you can avoid putting a large number of people in small rooms, you should do it,” Esper said.

The Defense Department scale for coronavirus runs from “0” — routine, with no community transmission — to Alpha, Bravo, Charlie and Delta.

Charlie indicates sustained community transmission. Delta means there is severe widespread community transmission.

The Army said previously it was closing some base gates to limit the spread of coronavirus that could occur during ID checks.

Those gates include Aliamanu Military Reservation back gate off Bougainville Drive; Fort Shafter Patch Gate (back gate) off Notley Street; Schofield Barracks Foote Gate off Kunia Road and Macomb Gate off Wilikina Drive; and Wheeler Army Airfield Kawamura Gate off Kamehameha Highway.

All Army fitness centers have closed.

At the Schofield commissary, meanwhile, “they are allowing 20 people at a time in the facility,” 25th Infantry Division Command Sgt. Maj. Mike Oliver said Monday. “This is to keep people spread out in the building.”