The emergency response from Florida Power & Light is “well underway” as Hurricane Ian approaches, the utility company announced Monday.

FP&L has mobilized 13,000 workers, as well as supplies, to ensure the response is conducted as safely and quickly as possible after the storm hits, according to a press release.

As the hurricane begins to bear down on the region, FP&L will use remote grid technology to restore power remotely during the storm, as long as it is safe to do so, the company said. After the storm passes and winds drop below 35 mph, FP&L will continue restoration and conduct damage assessments with field crews.

The utility company also urged customers to make preparations and take safety precautions.

"As this storm approaches Florida, we know our customers are counting on us and we are determined to meet this challenge," said Eric Silagy, chairman and CEO of FP&L in a statement. "We are mobilizing and pre-positioning our restoration workforce, so these brave men and women can quickly start working as soon as it is safe to do so."

-ABC News' Matt Foster

Florida State University has canceled classes Tuesday through Friday as Hurricane Ian approaches.

"The cancellation of classes on Tuesday is to allow students to travel safely out of the area if they so choose," the university said. "Students who choose to stay in Tallahassee will be advised via the FSU Alert system to follow a 'shelter in place' protocol during the storm."

The St. Pete-Clearwater International Airport will close at 1 p.m. Tuesday due to the mandatory evacuation orders in Pinellas County. The airport will stay closed until the evacuation order is lifted.

Mandatory evacuation orders are in place for coastal parts of Hillsborough County, Florida. Over 300,000 people are expected to evacuate, officials announced Monday, with emergency shelters opening at 2 p.m. Monday.

Hillsborough County could face up to 15 feet of storm surge and 30 straight hours of tropical storm force winds, Florida Emergency Management Director Tim Dudley said.

County Administrator Bonnie Wise added, “We did not make this decision easily, but the storm poses a serious threat, and we must do everything we can protect our residents.”

Some residents of Sarasota County and Manatee County are also under mandatory evacuation orders.

-ABC News’ Alex Faul

The Federal Emergency Management Agency's search and rescue teams have been out in the field since 4 a.m. Thursday, FEMA Administrator Deanne Criswell told "Good Morning America." It will prioritize saving lives and helping people impacted by the storm, who may be trapped.

Criswell said FEMA has been hearing reports of people calling 911 through the night and will use information it has gathered in those hours to prioritize rescues in harder-hit areas.

"This has been just a catastrophic storm and it's left significant damage in its path," Criswell said.

Criswell said FEMA will be able to conduct rescues by land, air and sea.

The most significant impacts have been happening in Lee County, where people are without power and water. Criswell also expects impacts across the western coast of Florida.

"Water is dangerous. Even though the storm has passed, the water that is there is still dangerous. There's debris, there's chemicals, there could be downed power lines. People need to be careful, they need to stay vigilant," Criswell said.