UK Cases:
https://www.kentonline.co.uk/tunbridge-wells/news/man-died-after-inhaling-poisonous-gas-from-church-vents-287166/
Danut Fotache, 37, died outside on 22nd January 2023 in Tunbridge Wells, Kent. He was leaning against a church wall close to a heating vent that he presumably thought would provide a little extra warmth as he slept rough through a cold winter night.
Frederick Cairey, 38, see Westminster Informer 21st May 2004.
Homeless man Frederick Cairey died in Belgravia, London in November 2003. He had been sleeping outdoors close to the exhaust vent for an office block boiler which was producing excessive carbon monoxide (press report erroneously states carbon dioxide, we have official confirmation that it was carbon monoxide).
USA Cases:
https://news.knowledia.com/GB/en/articles/university-of-cincinnati-soccer-player-21-inhaled-carbon-monoxide-d90fad6b0481fe409568ac13e68f16c5011cf071?source=rss
UC Bearcats midfielder Ally Sidloski, 21, drowned at East Fork Lake in Ohio on May 22 2021. She’d been hanging onto a swim platform. Inquest not yet held.
https://www.news5cleveland.com/news/local-news/oh-stark/northeast-ohio-couple-spreading-awareness-of-boating-dangers-after-losing-son-to-carbon-monoxide-poisoning Afton Taylor died in June 2019 in Northeast Ohio after carbon monoxide poisoning on a routine boat trip: his parents want to warn others.
https://www.today.com/health/mom-shares-warning-after-son-dies-carbon-monoxide-poisoning-t192631 Little Andy Free, aged nine, had been “curled up” at the back of his family’s Malibu Skier at Lake Eufaula in Oklahoma in early June, “slowly dying” of open air carbon monoxide poisoning his devastated mom wrote on Facebook