3 Dead GLW hens, hypothermia or illness?

[ChickenKeep01]

So about 5 months ago my GLW hen hatched her first full clutch of eggs with 11 hatching , we took 4 into hand raise and left the rest with her, everything went fine and i've sold most by now but a few weeks ago in Australia we had a very cold week with temperatures down to -4C at night, and this killed one of the young hens over a period of a few days , thinking nothing of it as i just assumed it was a combination of her age, she was the lowest on the pecking order, her being the smallest hen and the cold. A few weeks after that we had another cold week in which another faced the same fate again i just thought it was the cold so i did some work on the coop to try and warm it up a bit. And now i've got a third one in the same condition. She's so weak she can't even stand up, she is nothing but skin and bones and i doubt she'll make it to the morning (She is currently inside with us trying to nurse her back to health). But with this 3rd hen im not sure if it is the cold or if there could be a disease in the flock, does anyone know?. Her symptoms are, being extremely weak, cant even stand up, not eating or drinking much, extreme weight loss and not moving at all, all 3 have had the same symptoms, does anyone know if this is hypothermia or a disease?

Edit: The third hen just died.

 

[coach723]

Do you have resources in Australia for having a necropsy done? Sorry, I don't know anything about what is available there. Are all of these the 5 month olds? Since you have had 3 die with the same symptoms I would have one necropsied to get the real answer. I would think that the temperature alone would not do this, and the symptoms sound like something else is going on. A sick bird is much more likely to be impacted by the temperature than a healthy bird. If you have a virus affecting your birds then necropsy would be the best way to figure it out. I'm very sorry for your losses.