Massachusetts National Guard service members are scheduled to deploy Wednesday to emergency shelters across the state that are housing displaced and migrant families as part of an up to six-month call-up.

Gov. Maura Healey activated up to 250 members to serve more than 40 shelters that do not have contracted service providers. Uniformed troops will support logistics and administrative duties but the exact shelters they are serving will remain secret due to privacy concerns, a Healey spokesperson said.

The Guard activation is one of the few major moves Healey has taken under the state’s more than month-old state of emergency. The Healey spokesperson said the call-up is for up to six months, “however this is a rapidly evolving situation that will continue to be assessed.”

It was unclear Tuesday afternoon how many troops would mobilize at the outset of the call-up. Soldiers and airmen are being drawn from units across the state and the mission commander is Lt. Col. Patrick Donnelly, a Massachusetts National Guard spokesperson said.

“The Massachusetts National Guard’s role in the inter-agency response to support ongoing emergency shelter operations will expand to leverage our diverse and adaptable range of capabilities. The Guard is committed to ensure the safety and wellbeing of the residents of Massachusetts, and our emergency and domestic operation experience will add a wide array of options to assist those in need,” said Lt. Col. Donnelly, commander of “Task Force Shelter.”

The Guard spokesperson said service members were “receiving briefings on their expected tasks.”

Troops will assist with making sure food is delivered to hotels, arrange transportation for important appointments, help people access medical care, connect “clients” with child care items like diapers or baby formula, and help with enrolling children in local schools, a Guard spokesperson said.

Housing Secretary Ed Augustus said Guard members are a “key strategy” to take pressure off coordinators working at unstaffed shelter sites.

“This regional structure that’s going to kind of oversee multiple sites, I think that’s going to take down a lot of the kind of confusion and communication issues by having somebody right there on site,” Augustus said as he was leaving a meeting at the State House.

Lt. Gov. Kim Driscoll said soldiers will essentially create “rapid response teams” for hotel shelters that do not have professional staff.

“Coordination has been messy and a pain point for us trying to grow with all of [the municipalities] as we’re seeing rising numbers of families every single day. We think the deployment of the National Guard will help. That’s one of the reasons we did that. Logistics are a strong suit of their operation,” Driscoll said at a State House meeting of municipal officials Tuesday.

The deployment comes as the Executive Office of Housing and Livable Communities expects about 1,000 families — both local homeless residents and newly arrived migrants — to enter the emergency shelter system each month.

Guard members will arrive at hotels as lawmakers up their criticism of the Healey administration’s response to the shelter crisis. Top Democrats offered sharp takes this month on what they said was a lack of communication between the state and municipalities hosting shelters.

A Milton Democrat who helped lead the Legislature’s oversight of former Gov. Charlie Baker’s response to the COVID-19 pandemic called on Healey this week in a letter to come up with a more uniform command structure for the state of emergency.

“The administration does not seem to be utilizing a lot of the structures that we have in place for emergencies and crisis situations, at least on a regular basis, in a regular cadence, that would be done and has been done in previous events,” State Rep. William Driscoll told the Herald by phone Tuesday.

Rep. Driscoll said the state needs a structure to deal with an overburdened emergency shelter system because “this is a long duration event.”

“What’s at stake is the weeks and months ahead. This is a long duration event. There will continue to be more and more immigrant arrivals, and we need a structure that’s going to be able to deal with that as it comes,” said Rep. Driscoll, who co-chairs the Legislature’s Emergency Preparedness and Management Committee.

Augustus said he has not yet seen Rep. Driscoll’s letter but he is “sure we’ll put a response together.”

“It’s a fast moving situation where we’ve got an incident command structure that was established back in May,” Augustus said. “It’s continuing to be staffed out and expanded upon as we confront new and different challenges and the volume of folks that we’re dealing with and the number of locations that we’re dealing with.”