How to look after pigeon eggs?

I had a nest in my garden which has fallen down, the mum was sitting on it but she must of stopped when this happened. Im not sure how long ago this was but the eggs stayed in the tree which i managed to retrieve she had been sat on them for at least 6 days before this happened and ive done the candle test in which i could see a little dark circle with some veins and an air space i don't know how to tell if their still alive or not so any information would be helpful. To keep them incubated ive been holding them in my hands as there meant to be kept at about body temperature i wondered if i could leave them to incubate in an airing cupboard. Thanks.