Hello Dave. Some of the information you have been given is okay. Some of it is a bit of hooey. Keeping him warm is good but be very careful how you are doing it. Whether what you are doing is safe or not depends on the type of space heater and whether you bird can get a way from the heat if he needs to. Keeping them as near 85F as possible is what we want and the best way to do that is to use a heating pad, only under the rear half of the cage or smaller enclosure. Using only the low setting and having only under half will allow him to move away from it if needed. Getting over heated is as bad as getting chilled. Millet is a high fat grain and normally should not be more than an occasional treat. However when a bird is ill, it is often a favorite so it can help keep them eating when they might not be interested in anything else. I don't know who would have said anything about charcoal to unless they know nothing at all about birds. Do not do anything like that. We never want to try to medicate bird when we have no clue what is really wrong with it. I cannot diagnose for you from long distance but I highly doubt this is a "stomach" problem. More than likely it's bacterial, fungal or a combination. Only a good Avian vet can tell you by checking a stool sample under a microscope. Then only the Vet can give you proper antibiotics. Don't waste your money or your bird's time on any of the over the counter junk from a pet store. If they had anything that would work, you would not be able to buy it without a prescription and you would definitely not foul his drinking water with it. The only thing you can do for him at home is the supportive care until you can get him to a vet. And you need to do that asap. With these symptoms, he has been ill for a while now. All birds have a very strong instinct to mask their symptoms. It's a critical survival tool in the wild and it carries over to our caged birds. By the time we see the symptoms you describe, it's because the bird is too ill and too weak to keep up the pretense. In case you don't know of a vet who is well trusted with birds, I can give you some links that I hope will help. If you have any more questions about any of this, don't hesitate to let me know but I'm really afraid you will lose him if you don't get him in right away. I'll keep the little guy in my thoughts. Patricia