Several Florida hospitals which sit in the path Hurricane Irma is expected to take this weekend have begun evacuating patients, while others will remain open during the storm and only postpone elective procedures.

As of Friday morning, Irma is a Category 4 hurricane, meaning its winds range from 131 to 155 miles per hour. The storm is expected to approach the Florida Keys and the state’s southern tip late Saturday night, make landfall near Miami early Sunday morning and then make its way up the peninsula, according to the National Hurricane Center. Evacuation orders have been issued for parts of Miami area and areas farther north like Jacksonville.

The first of the state’s hospitals in its path are on the Keys. STAT News reports three of them—Lower Keys Medical Center, Mariners Hospital, and Fishermen’s Community Hospital—have been discharging patients and evacuating others. Lower Keys had transported between 10 to 13 patients to Gadsden Regional Medical Center in Gadsden, Alabama. Mariners and Fishermen’s are both owned by Baptist Health South Florida, the largest system in South Florida, and patients there were planned on being moved to other facilities in the Miami area.

“Our emergency plan goes beyond storms to include the outbreak of diseases and man-made disasters. It’s always best to be prepared to ride out the storm,” Baptist Health's COO, Wayne Brackin, said in a statement.

In Miami-Dade County, where more than 100,000 residents have been ordered to evacuate, not all hospitals are doing the same. The county’s public hospital system, Jackson Health, said in a statement it would enter a state of emergency beginning at 7 a.m. on Saturday. Appointments at primary care centers have been cancelled to focus on hospital operations, with all its hospitals and emergency departments remaining open.

The University of Miami Health System has a similar plan, with outpatient services and ambulatory clinics already closed as of Friday and remaining shuttered through Sept. 11. Mayo Clinic’s Florida campus expects to do the same, closing its outpatient clinic Friday afternoon. But not all hospitals in the area are staying open. HCA’s Mercy Hospital Miami began evacuating 200 patients on Wednesday and closed its emergency room to new patients.

Farther north, hospitals are also preparing, though Irma will likely weaken as it moves up the Florida peninsula. Florida Hospital—ranked the best in the Orlando area by U.S. News and World Report—said in a statement its campuses around the region will remain open.

“We have stockpiled thousands of gallons of water, generators are standing by to run the hospitals on emergency power if necessary, and sandbags have been deployed to secure doors and windows,” the hospital said in a statement. “Family members of patients can rest assured that the hospital will be a safe place for their loved ones during the storm. We will be fully staffed and continue to deliver our excellent standard of care.”

The preparations in Florida follow what many Texas hospitals did before, during and after Hurricane Harvey hit the state, bringing with it record rainfall of up to 52 inches.