While we're on the topic of carbon monoxide:
A 17.5 million dollar lawsuit was pursued after a hotel decided to bypass the carbon monoxide detector on the boiler. The detector had switched off the boiler for safety reasons while staff simply bypassed it to please the hotel occupants need for hot water. The air conditioning system sucked up the carbon monoxide leaving some with illness and some with
brain injury.
Remember Carbon Monoxide is a 'colourless' and 'odourless' gas that left unchecked will prove fatal.