I get it now, to keep them warm you had to unintentionally give them Co2. Being in the states, this type of situation doesn't usually occur. What can help that in your future hatches is to add a heat sink to your incubator to hold temps for longer. In other words, in any space not used for eggs or air circulation, put in jars or baggies of water as they will keep the temperature up for longer when the power does go out.