The song received widespread critical acclaim, praising its musical style, lyricism, and Welch's vocal performance.

[10] Lyrically, the song is a "more unconventional and darker tone for the band" in comparison to their previous singles, which some critics classified as "haunting".

I recorded it with Paul one evening, using a lot of strange reversed vocal samples and big hip hop piano.

[7]Mayer Nissim from Digital Spy, said the song "combines the chills of a classic horror flick with the intensity of a tragic romance collapsing in on itself like a swirling black hole.

Nima Baniamer of Contactmusic.com gave the song five stars writing, "With lingering vocals and an eerie melody, this track goes beyond the supernatural to create something purely magical.

"[9] Dara Hickey of Unreality Shout also gave the song five stars writing, "'Heavy in Your Arms' is easily one of Florence's best singles (and album tracks) to date, marrying sinister samples and twisted lyricism to make a perfectly gothic love song, but also managing to retain sentiment and desperation through her vocal performance.

[10] Mayer Nissim of Digital Spy gave the song another five-star rating, calling it a "brooding mix of dark samples, twisted choirs and piano back Welch's almost spoken-word verses, leading up to truly ear-shattering choruses which sound unlike anything else in the charts right now", while naming it the band's "best single to date".

The video, filmed entirely in black and white begins with Welch laying in a bed while being carried by the arms of a person hidden in the dark.

O'Donnell compared its production to The Blair Witch Project's "lofi style", and the Victorian era costumes to those from Kate Bush's videos.

[6] A contributor to Stereogum compared the visuals to the Toadies' "Possum Kingdom" and Tom Petty's "Mary Jane's Last Dance" music videos.

[18] The band also performed the song on 10 July at the Oxegen Festival,[19] and at the Late Show with David Letterman in 16 December of the same year.

[21][22] The band also performed the song on 7 November 2010 at the Wiltern Theatre, Los Angeles, being later released to the iTunes Store on 28 June 2011.