Taylor Swift: Single makes me sweaty

Taylor Swift is in a "full body sweat" after releasing her new single.

The 24-year-old musician collaborated with fun. guitarist Jack Antonoff to record Out of the Woods, which they made available on iTunes today.

It shot straight to number one, and it seems Jack and Taylor are as excited as their fans. The Shake It Off singer posted a text conversation between herself and Jack, in which he admitted to "literally" running into two walls while walking his dog with Lena Dunham, Lamby, because he couldn't stop looking at his phone.

"I am in a full body sweat," came Taylor's reply.

"Clearly, we are very nonchalant about the whole thing. #whereismyCHILL #outofthewoods (sic)," she captioned the screen grab.

In a recent YouTube video, the blonde singer spoke about the lyrics to the tune. She's known for writing about love and relationships and this song is no different, with speculation it could be about her brief fling with One Direction's Harry Styles.

"This was a relationship where I was kind of living day to day," she explained. "It was a relationship where you kind of never feel like you're standing on solid ground."

Jack's girlfriend Lena is a close friend of Taylor's and it seems she couldn't be prouder of their success. She uploaded a snap of the first time the pair worked together on Instagram and also took to Twitter to share her delight.

"Oh um excuse me @taylorswift13 & @jackantonoff put a song out like 11 minutes ago and it's already #1 on iTunes (sic)," she proudly told her followers.

Out of the Woods is the second single taken from Taylor's upcoming album 1989, which is out on October 27.