Travolta, Phoenix immersed in fiery research

John Travolta and Joaquin Phoenix are immersed in research for their latest movie Ladder 49 - so much so that producers are worrying they will come to harm in their enthusiasm for fire-fighting, according to imdb.com.

The pair, along with co-star Balthazar Getty, spent a month with real fire-fighters in Baltimore, Maryland to get hands-on training for their roles but their enjoyment sparked grave concerns in the people paying their salaries.

Getty recalls: "We went out on a real call and into a real fire, and there was no supervision. It was just us with the fire-fighters, and they didn't care. It was exhilarating, and it was scary.

"You're with these guys in your turnout gear, you've got your tank on your back, and you almost feel like you can walk right into it and not get hurt. Once the producers realized what we were doing, they put a stop to it. We got a big memo saying, 'You are no longer allowed to do ride-alongs with the fire department'."