To keep warm, they turned on the water heater and took hot showers at about 1am.
And because of that, they wound up in hospital after suffering carbon monoxide poisoning.
The men, reportedly in their 20s, were staying at friend’s home in Taipei’s Xinyi district.
As it was cold, they had shut all the doors and windows before bathing and kept them shut after that.
Later, they felt dizzy and dialled 119 for an ambulance.
Firefighters and paramedics were sent to the scene, and the men were taken to hospital.
Firefighters say that they suffered carbon monoxide poisoning due to the gas emitted from the water heater and the lack of ventilation due to the shutting of all doors and windows.
The Taipei fire department has warned the public to keep at least a window open if you’re intending to use the water heater to shower.