Do I need to evacuate? How to stay safe as Hurricane Ian approaches Florida's coast.

Authorities are urging millions of Floridians to evacuate as Hurricane Ian is expected to soon hit the state with extreme winds, catastrophic flooding and life-threatening storm surge.

Various evacuation orders have been issued in counties along Florida's west coast, where the hurricane is expected to make landfall on Wednesday. Residents in some areas of Tampa, Florida’s third most-populated city, are among those being asked to leave their homes.

"If you're told to evacuate, evacuate now. Not tomorrow. Evacuate right now," said Florida Senator Rick Scott on CNN's "The Lead" Tuesday afternoon.

Scott said the storm surge could be especially deadly and that many residents will have never experienced a storm so severe.

"We know there's going to be a lot of storm surge, so if your local emergency officials are telling you to evacuate, that's because there is a high likelihood of serious wind, rain and water coming you way," Red Cross spokesperson Evan Peterson told USA TODAY.

Here's who needs to evacuate and how to evacuate safely:

Should I evacuate? Which Florida counties are evacuating?

You should follow recommendations from local authorities, which can be found on the Florida Division of Emergency Management website.

On Monday and Tuesday, counties including Charlotte, Hillsborough and Lee had issued mandatory evacuation orders for some residents.

As Hurricane Ian makes an expected landfall on Wednesday, an area spanning from Naples, Florida, to counties north of Tampa, Florida, will likely see the heaviest impacts, officials have said.

What's a voluntary evacuation? What are zones?

Local officials have issued both mandatory and voluntary evacuation orders for areas in more than a dozen Florida counties.

If your area is under a voluntary evacuation, it means you are encouraged to leave and you should at the minimum prepare to evacuate.

Evacuation zones are predefined areas based on hurricane risk. They are named after letters of the alphabet, starting with A — the highest risk zone. Each zone is determined based on storm surge data, elevation and evacuation routes, according to Charlotte County, Florida.

Where should I go in an evacuation?

People who are asked to evacuate don't necessarily have to travel far to reach safety.

"In order to get out of the way of this storm ... you don’t have to go hundreds of miles to get to safety, you may have to go tens of miles," Peterson said.

It's important that people leave areas likely to experience flooding, because it will become much harder for emergency responders to reach residents after flooding has occurred, the American Red Cross says.

Going inland via set evacuation routes will help protect you against hurricane impacts, Peterson said.

Floridians are being told to ride the storm out in a shelter or stay with friends, family or in a hotel or motel in a safer area. You can find a shelters on Florida's emergency management website.

What should I bring with me if I'm going to a shelter?

Bring enough food, water, clothes and other items for you and members of your group if you're planning to spend time at a shelter this week, the Red Cross says.

Red Cross workers will accept domesticated pets, they just need to be crated if possible, the non-profit says.

If you're headed to a shelter, plan to bring the following items:

• Prescription medications

• Extra clothes

• Pillows

• Blankets

• Soap, deodorant and other hygiene supplies

• Other "comfort items"

Don't forget to bring diapers and baby formula for young children, the Red Cross says, along with any other items members of your family may need.

Also bring any financial, medical, immigration or other important documents you wouldn't want the storm to destroy if left at home.

Have a plan in place for how you will receive emergency notifications and weather updates, Peterson said. He recommends having at least three devices, including one that doesn't need to be charged through a wall outlet, like a battery-operated radio.

Do I really need to evacuate?

Experts say the best way to stay safe ahead of a hurricane is to follow evacuation orders and get out of the path of the storm. People who stay are putting themselves in harm's way.

"You can rebuild that house, but you can't rebuild your life," said Scott on CNN.

Since impacts from Hurricane Ian are expected to be severe and life-threatening, anyone who does not evacuate should be prepared to be unable to receive help from emergency responders post-storm, Peterson said.

Ride-hailing service Uber announced Tuesday it will expand its free rides to and from state-approved evacuation shelters to Lee, Charlotte and Sarasota counties. On Monday, it offered the same to residents in Hillsborough, Pinellas, Manatee and Pasco counties. Uber customers wanting the free ride should type "IANRELIEF" into the promo code when reserving an Uber ride.

If a person finds themselves at home amid severe weather, they should go to a room with no or few windows and avoid windows and glass doors during the storm, emergency management experts say.

HOW TO PREPARE: Our homeowner’s guide to hurricane preparedness

Contributing: Douglas Soule, USA TODAY Network Florida

This article originally appeared on USA TODAY: Hurricane Ian evacuations: Who should evacuate; where to go