Most likely they would need a replacement canary. For humans the aftereffects of carbon monoxide poisoning can last for weeks. Canaries will probably need some

Most likely they would need a replacement canary. For humans the aftereffects of carbon monoxide poisoning can last for weeks. Canaries will probably need some time to recover too. If the canary doesn’t chirp, it probably does not function well as a warning system. You need to keep checking on it visually, which means you can only work within sight of it, and this limits your ability to work.