If your guinea pig has a fever he will probably become dehydrated. Try offering him some grated apple or small pieces of orange. DO NOT medicate your guinea pig on your own. If your vet is not available, find one that is. Many vets will have emergency services when they are away. If you can locate an animal hospital nearby, they will have an emergency room and treat your pet. Or call your local shelter to ask what they recommend. Guinea pigs are small animals and can be very sensitive to any medications which should only be prescribed by a veterinarian.
