Glass is a bad insulator, which means the tank will quickly adapt to the room temperature when our heater fails due to a power outage. In order to keep the temperature as stable as possible blankets or Styrofoam come in handy. The risk of overheating can be avoided by placing ice cubes in a sealed plastic bag in the aquarium. Once the power is restored make sure to slowly adjust the temperature back to normal as extreme changes can cause extreme stress for your fish. Oxygen Oxygen levels in your aquarium will decrease with the increase in water temperature.
Oxygen enters the water through a gas exchange at the water surface.
If you think about blowing air into the plastic tube connected to your air pump, the effects will be very limited. The air stone actually provides little to no oxygen. To increase oxygen levels you should extract some water with a cup and pour it back in the tank. This should be repeated at least once per hour, or as soon as you notice your fish gasp for air. Lower tank temperatures will not only hold more oxygen, but also slow down the fish's metabolism.