BOSTON -- The man who inspired people around the world to dump buckets of ice water over their heads to raise millions of dollars for Lou Gehrig's disease research is back in the hospital and is keeping his sense of humour.

A Facebook post from the family of 32-year-old Pete Frates said he is resting comfortably at Massachusetts General Hospital and that "doctors, medicine, prayers and love continue to help him get stronger."

After some news outlets erroneously reported Monday that he had died, Frates responded by posting a 45-second video on Twitter showing him lying in a hospital bed while the song "Alive" by Pearl Jam plays in the background.

Frates' family said Sunday that he had returned to the hospital and was "battling this beast ALS like a Superhero."

He was diagnosed with amyotrophic lateral sclerosis in 2012. The disease weakens muscles and impairs physical functioning. There is no known cure.

The ALS Ice Bucket Challenge raised more than $220 million when it took off worldwide on social media in 2014.