In the show, an Austin, Texas, fire station that lost most of a crew in a blaze hires New York firefighter Owen Strand (Lowe) to rebuild the team, and Michelle Blake (Tyler) is a paramedic often on the same emergency scenes.
"They offered me the part, and I think we started filming two weeks later," Tyler said on a Television Critics Association panel. "So I had to do a lot of training very quickly and look like I know what I'm doing."
Like the original 9-1-1 and other medical shows on television, Lone Star has technical advisers who trained Tyler as the scenes required.
"A lot of the extras and people in the scenes with us are actual firefighters and paramedics," Tyler said. "In all those moments in between on set, I can ask a million questions and observe."
Lowe got close with firefighters independently of 9-1-1: Lone Star. His Santa Barbara home has been close to wildfires, so he's gotten to know the real firefighters combatting the California blazes.
"I had them staged at my house," Lowe said during the panel. "I was feeding them. I was really interested in why these men and women do what they do, what does it mean to them, how do they go and sleep in the dirt for weeks on end, if it comes to that, pull the kind of hours."
The actor had a bit more time to shadow firefighters before filming 9-1-1: Lone Star. Lowe felt bad accompanying firefighters on the calls because people didn't know what to think when they saw him.
"So I'm with the fire brigade and they're right by the area where Dodger Stadium is," Lowe said. "That is an issue when you go out and train. People are like, 'I don't feel so safe with Rob Lowe standing there. I don't feel like the real experts showed up.'"
With two 9-1-1 series on Fox, viewers are going to see double the elaborate emergencies. Lone Star begins conservatively with a fire and an automobile accident. But even the standard emergencies were thrilling to film, Tyler said.
"The first time we had a big scene with this car crash, it was like going to Universal Studios, like to the theme park," Tyler said. "It was an upside-down car. All the real firefighters were there. Then we come in and we have to do this; it's almost like a choreographed dance or a stunt."
Tyler said even fictional emergencies trigger adrenaline.
"When you're in the emergency moment, it's the training that makes you stay calm when the [expletive] hits the fan," Tyler said. "So I get out of breath and I get very nervous and I'm trying to keep it together."
Besides the intense emergency situations, 9-1-1: Lone Star is also a father/son drama. Strand's son, TK (Ronen Rubenstein), is a recovering addict. Strand brings him along to Austin to help monitor his recovery. He becomes a father figure to his new firefighter recruits, too.
"Listen, I have two sons," Lowe said. "The notion of trying to herd the cats of younger people finding their way through the world, which is sort of what's going on when you're running a fire station, just felt really natural to me. I think these captains are the fathers of the people in the house, so that was very easy for me to relate to."
9-1-1: Lone Star premieres Sunday night on Fox after the NFC Championship game.