Found a few ways to cool down a feverish chicken. She was on an antibiotic and anti-inflammatory but is didn't seem to be working well. At first, I settled her in a bath of warm water, lowering her into it by slight pressure on her back. Spread out her wings to cool under arm-pits. She seemed quite happy and was much more interested in food and water. Also gave her aspirin, which definitely worked. Dose I found on many sites was 1/4 of 325 mg plain old-fashioned aspirin. Trial and error, I found that 1/2 tablet did a better job. Cut it in quarters and popped them in the back of her throat, then closed her mouth and she swallowed. The last day (a Sunday - no vet available), she was very, very ill and I didn't want to do the bath. Had a brain wave to wrap a bag of frozen vegetable in a towel and sit her on it. I could also carry her around with it. She stopped panting and seemed more comfortable. Thought I'd pass on this idea in case it might help someone else. She's now at the vet. They kept her overnight to tube feed her a she hadn't eaten in at least 24 hours This an avian vet, so she is in every good hands.