Everyone knows the saying about ravens: dark wings, dark words. But what do white wings represent?

Sansa Stark (Sophie Turner) knows the answer all too well. In the season six finale of Game of Thrones, a flock of white ravens were released from the Citadel in Oldtown, signaling a change of seasons in Westeros. It fulfilled the promise of Lord Eddard Stark's most famous saying: "Winter is coming." Leave it to Sansa to update the phrase, as soon as she saw the white ravens soaring through Winterfell: "Winter is here." It's an ominous proposition for the character, and it was equally upsetting dialogue for Turner, iconic as the line may be.

"When I said the line, that 'winter is here,' I knew what it meant," she tells The Hollywood Reporter. "It meant snow machines. Everybody hates snow machines."

Just as winter is creeping across the Seven Kingdoms, the Game of Thrones production itself waited until colder conditions presented itself before filming on season seven began — a development that led to the show's later-than-usual return this year. The conditions were brutal at times, especially for those involved in Northern combat sequences, like Richard Dormer, who plays the Lightning Lord Beric Dondarrion. "It was cold. It was very cold," he says. "It got down to -27 at one point. Fighting in cold weather is really difficult." For others, winter wasn't much worse than battling it out with snow machines.

"You eat a lot of fake snow," Turner says, defending her grievance.

"It wasn't completely cold and miserable," says Nathalie Emmanuel, who plays Missandei, one of the foremost players in the Daenerys Targaryen (Emilia Clarke) regime. "We shot in Belfast a lot more than we usually do, but we still got to shoot in Spain, just to clarify."

Surprisingly, some of the actors were quite hot over the course of shooting season seven. Take Emmanuel's onscreen love interest, Jacob Anderson, for example. Anderson, who plays the Unsullied leader Grey Worm, says that his character is not exactly a fan of Westeros' cold weather (or their customs, for that matter), but the seasonal shift was actually quite refreshing on a practical level.

"It was really hot. We're wearing winter clothes in a very hot studio," says the actor, who adds that the wardrobe change was an improvement from the Unsullied armor he's worn in the past. "I have scars on my body from that tunic. It's very hard leather that just digs in. Now, I have an undercoat, and that's really comfortable, even if it does get a little bit hot sometimes."

Other actors managed to avoid the cold, at least in part, by escaping to corners of Westeros where winter hasn't quite yet hit in full force — folks like Samwell Tarly, who left Castle Black back in season five in order to do research on White Walker weaknesses at the Citadel in Oldtown.

"Just as winter has come, he's gone down south," says Bradley, who plays Sam. "He's smart. He was checking the weather forecast. Winter may be here, but Sam isn't. He has his feet up. He's twisting by the pool at the Citadel. He doesn't have to worry about the weather at all."

While the experience of filming the show's turn for the cold varied from person to person, everybody in Westeros will eventually feel the freezer-burn. After all, the ominous words of House Stark aren't evolving here in season seven without major ramifications for all involved.

"I think it really means the conclusion is here," says Isaac Hempstead Wright, who plays the all-powerful Bran Stark, about what "winter is here" means thematically. "The fact that it never really did arrive for so long was the show's way of saying winter is the end. And in many ways, it is the end, in terms of the seasons. It's when everything dies, and the plants go away. The fact that that's finally happening [on the show] is quite ominous. This is the end game. There's nothing beyond this."

Winter begins when Game of Thrones premieres July 16. Follow THR.com/GameOfThrones all season long for news, interviews, theories and more.