"I'm spending my days running around in the jungle with no phone signal, so I don't have the time," Larson told ET's Nancy O'Dell at the Screen Actors Guild Awards. "I have no service to try and find a dress."
But the difficult conditions were worth it and definitely helped in bringing the story to life.
"It will be the most thrilling action," Hiddleston promises. "It will feel very rugged and raw and exciting."