For Milly Alcock, the hardest part of re-creating Westeros isn't the dragons—it's the heat.
The House of the Dragon star shared that because the series only uses "source" lighting—meaning they emulate lighting that would happen naturally in the world of the show, like sunlight, moonlight or torchlight—Alcock says it can get a bit steamy on-set.
"Because there's no electricity in this world, everything is lit by fire," she explained to The Hollywood Reporter in an interview published Aug. 30. "So all the lighting that you see in the show would have people that come around and light everything on fire and the set would get incredibly hot."
Because of all this fire, Alcock, who plays Princess Rhaenys Targaryen, says two girls with hair dryers would cool her sweaty armpits—something the Targaryen rulers only wish they could have.
But the heat wasn't the only challenge for the actress, who exclusively told E! News that filming the dragon-riding sequences was not her "favorite thing." The sequence required the actors to sit on a rig in front of a screen that projects the landscape from the show in the background.
Milly wasn't the only House of the Dragon star who had to adjust to using the dragon rig. Her co-star, Eve Best, who plays Princess Rhaenys Velaryon, told E! News how she felt about the dragon-riding scenes.
"It's a machine and it's moving about, and you have to move like you're on a motor bike which I've never done before," she noted. "You're strapped in a harness and there's wind in your face. It's just quite weird, but it was also quite lovely."
House of the Dragon has already been renewed for a second season after the show broke records with its Aug. 21 premiere—according to the network, the debut episode saw the largest audience for any new original series in HBO history. The show takes place 200 years before the events of Game of Thrones, when the House Targaryen ruled over Westeros. In addition to Alcock and Best, the show stars Tom Glynn-Carney, Emma D'Arcy, Rhys Ifans, Emilia Carey, Olivia Cooke, Steve Toussaint, Fabien Frankel, Sonoya Mizuno, Paddy Considine and Matt Smith.
House of the Dragon airs Sundays at 9 p.m. ET on HBO and HBO Max.