(CNN) For Disney World's most ardent fans, tomorrow is indeed only a day away.

Disney World is the biggest of big deals in the theme park universe. And the eyes of the theme park world will be on it this weekend.

1. Reservations and capacity

Two of Walt Disney World Resort's parks are set to reopen Saturday: Magic Kingdom Park (pictured) and Disney's Animal Kingdom. EPCOT and Disney's Hollywood Studios are slated to reopen on July 15.

Matt Stroshane/Walt Disney World Resort

Guests must follow four steps to use the system:

1. Get a valid park admission linked to a Disney account you've set up online.2. Register the members of your party.3. Select a date and a park to attend.4. Finally, review and confirm your reservations.

For instance, at 1 p.m. ET Friday, there were no parks available for annual passholders in July. But August had some availability, especially on weekdays late in the month. People already holding theme park tickets or who have a Disney Resort reservation still have openings and options in July. Right now, spots for Hollywood Studios in July are particularly hard to come by.

As the situation is in constant flux, you might need patience and flexibility at first. Or you might get lucky and snag your top choices right away.

CNN Travel will be looking at how the new system works and what level of crowds Magic Kingdom and Animal Kingdom attract on Saturday and beyond.

Florida has seen some of sharpest spikes in Covid-19 cases in the United States and the world recently. No one can predict how that might affect things in coming weeks.

2. Temperature screenings

All guests will be required to a undergo temperature screening before entering a theme park at Walt Disney World Resort.

David Roark/Walt Disney World Resort

By now, it should be no surprise to theme park guests that they'll undergo a temperature screening before being allowed in. Here's what Disney says to expect:

"All guests will be required to undergo temperature screenings prior to entering a theme park. Based on guidance from the Centers for Disease Control and Prevention, anyone displaying a temperature of 100.4 degrees Fahrenheit or higher will be directed to an additional location for rescreening and assistance.

"Those who again measure 100.4 degrees Fahrenheit or higher will not be allowed entry, nor will those in their party," Disney said.

Schaffner said that back-up reading should prevent most problems.

For someone who does pop the 100.4 limit, he said "if that person goes under tent, gets a cool drink, and is permitted to rest, they'll cool down rapidly enough to past the test -- assuming they are not ill and do not have an infection."

Disney told CNN Travel on Thursday that secondary screenings take place in a cooler, tented area several minutes after the initial reading.

Dr. Shannon Hopson, an endocrinologist in Corvallis, Oregon, shared her second opinion: "You can get an increased body temperature from being overly hot, but I wouldn't think this would be particularly common."

Worried anyway?

Hopson's advice is to make sure you're well-hydrated before you get in line and shield your face with a hat or a cap with a big brim. She also said set your appointment for a morning arrival if you can so you'll arrive when it's cooler.

Hopson is actually more worried about potential Covid-19 carriers that temperature screenings won't catch.

"The biggest problem with temperature screenings is that they can provide a false sense of security. They're everywhere. We do them for patients and all staff at my office, but they only catch the sick people," Hopson said. "We know that asymptomatic carriers can spread coronavirus as well as sick people, so there's just no way to screen those people out."

We'll be watching how temperature checks are going -- and how the public reacts to them.

3. Dining

Guests at Disney's Riviera Resort can see Minnie, Mickey and the gang during breakfast at Topolino's Terrace -- Flavors of the Riviera, the resort's rooftop restaurant. During the phased reopening, characters will maintain proper physical distancing while parading through the restaurant.

Matt Stroshane/Walt Disney World Resort

Like restaurants anywhere else, Disney has had to upend its normal dining experience and find new ways to deliver food and drinks to hungry and thirsty guests.

In a news release, Disney said "new measures promoting health and well-being will be implemented." You can expect to see "enhanced cleaning in seating, dining and common areas, as well as changes to self-serve options."

-- You'll need a face covering when entering and leaving dine-in restaurants, but obviously they can be removed when you're seated and you're ready to eat.

-- If you're a day guest, you'll absolutely need a reservation for dining at a Disney Resort restaurant. And if you're an overnight guest, it's highly recommended.

-- Wherever possible, Disney is offering cashless and contactless exchanges.

4. Character interactions

Mickey Mouse will star in the "Mickey and Friends Cavalcade" when Magic Kingdom Park reopens.

Olga Thompson/Walt Disney World Resort

Perhaps the most cherished memories from a Disney visit are children rushing with mad joy into the arms of a beloved character. Unfortunately, it's a look-but-don't-touch policy for character interactions with Mickey and his pals during the pandemic.

But Disney will be making it a visual spectacle.

In the Magic Kingdom, "characters will cavalcade along the traditional parade route throughout the day." And over at Animal Kingdom, guests might witness "Disney characters setting sail down Discovery River on special boats, such as Donald Duck, Daisy Duck, Pocahontas and others."

We'll be keeping an eye out for how these encounters go. Will the kiddies still enjoy these sightings and be able to live without the hugs?

5. Rides and lines

Ground markings will help promote proper physical distancing in attraction queues. And rides won't be filled to capacity.

Matt Stroshane/Walt Disney World Resort

So there's not much point in limiting park capacity, requiring masks and keeping characters apart from guests and then letting folks bunch up in attraction lines and on the rides themselves.

To that end, you'll be seeing signs for social distancing in queues. And rides will be sent out with empty seats, with only people in the same party bunched up together.

In its news release, Disney said it expects to open up very popular attractions on Saturday such as Space Mountain, The Haunted Mansion, Pirates of the Caribbean and the Seven Dwarfs Mine Train.

Tremaine says to keep in mind there are no Fast Passes for now in the Magic Kingdom. Rides are first-come, first-served.

We'll be watching how the combo of fewer people in the park vs. social distancing on the rides plays out. Will waits be shorter, longer or about the same?

6. The Disney experience during the pandemic

Ground markings will help promote proper physical distancing outside retail shops. How will such measures go over?

David Roark/Walt Disney World Resort

Perhaps the most fascinating aspect of the reopening will be the reaction of the guests to all the new safety measures. After all, a July 2020 visit is going to be very different than what guests enjoyed pre-pandemic.

Tremaine said, "The safety measures at Universal Studios and Dollywood [in Tennessee] haven't put much of a dent in my enjoyment of the experience. Hand sanitizer before rides and distancing between parties isn't that hard to manage."

But what about a face mask? And in a sticky Orlando summer, too.

"It definitely isn't ideal to have to wear a mask right now. I know Disney die-hards who say they won't go back until they don't have to wear masks. But I think for a lot of people, we're willing to put up with the heat and inconvenience and discomfort of a mask if it means we get to be somewhere we love," she said.

"It's been a really bad few months. If a mask is the tradeoff for a little bit of pixie dust in our lives, so be it."

Disney has confirmed they are designating specific areas where families can take a break and take off their masks.

"It's great time to point out that we, as theme park guests, often don't realize how much work is going on behind the scenes at the entertainment attractions that we visit," Lewison said. "Even the smaller regional amusement parks are pretty complex operations, and Covid has added another layer of intense complexity over what is already a complicated operation."

He said guests should keep in mind that "theme park employees also have to be temperature-checked, social distance from each other, wear masks and take meals and breaks in safe situations. They're also in unfamiliar circumstances. Parks now have a trickier balance between their permitted capacities and visitor demand and staffing."

His assessment of their efforts?

"What I've seen is that the parks have taken on a huge challenge and they're doing an amazing job with it in a very uncertain new environment."

Lewison had some advice for people going Saturday and beyond.

The "top tip is always: Make sure that you carefully follow all park rules and regulations, from signage to cast member instructions. If you're unsure, ask a cast member."

He said to be prepared for some attractions to not be available. As for the rides that are operating, guests should also expect to see some changes.

In the end, it's all about preparation, said Lewison.

"Make sure you have a comfortable mask, comfortable shoes, sunscreen, hat, hand sanitizer (just in case, although parks have done a lot to provide it), reservations, phone charger, water ... all the usual stuff that improves your day at a theme park."

Finally -- "Have fun! You're one of the lucky few at a theme park, and I'm jealous!"

CNN's Natasha Chen contributed to this report.

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Disney World's July 11 reopening: 6 things to watch - CNN