Rodney Knight, an associate professor at Université de Montréal's School of Public Health, says he is skeptical about claims people are confusing poppers with popular energy shot drinks and falling ill or dying.

Source: https://www.cbc.ca/news/health/fda-poppers-energy-shots-warning-1.6863960?cmp=rss

The chronic or heavy inhaling of poppers can cause a condition called methemoglobinemia, which starves our cells of oxygen and can be life-threatening.

Source: https://gizmodo.com/fda-warns-that-poppers-are-not-energy-drinks-1850479587