Final answer:
If oxygen fails to flow from the humidifier, you should check the water level, temperature setting, and oxygen concentration.
Step-by-step explanation:
If oxygen fails to flow from the humidifier, there are a few things you should check. First, check the water level in the humidifier. If the water level is low, it may be preventing the oxygen from flowing properly. Next, check the temperature setting of the humidifier. If the temperature is set too high, it may be causing the oxygen to evaporate before it can flow. Lastly, check the oxygen concentration. If the oxygen concentration is low, it may indicate a problem with the oxygen supply or the humidifier itself.