It could be an internal infection or something of that nature. Sometimes, if something is occurring inside the body, it may be hard to tell on the outside. I would most certainly recommend taking them to the doctor.
It could be possible, or it could be a sign of a fever.
The main symptoms you will experience if you are suffering from diverticulosis are diarrhea and cramping abdominal pain, without any fever or infection.
It depends on the illness you have. If you have food poisoning you will have a fever and if you have the flu you will have a fever but the rest of your symptoms will be different.
The symptoms are same, but tend to be milder. Symptoms of typhoid are fever, (which goes up by step ladder pattern), weakness, headache. (Headache is very uncommon in children.)
A fever is the body defense system to kill the virus or bacteria in the child. The temperature itself causes no harm according to doctors unless the fever reaches 105 degrees. The symptoms, however, are certainly no fun to deal with. If the fever persists, take your child to their primary care physician especially if anything seems out of place or abnormal about his/her condition as a fever could be a symptom of a bigger problem such as an infection.
If the symptoms are severe as you say, these could be symptoms of a serious infection. Most people faced with these symptoms in an infant would contact a medical professional urgently, or go to the Emergency Room for treatment, especially if there is a combination of fever and rash.
A fever is a symptom.
It could, but other illnesses have those symptoms, too.
There are many reasons why a cat might have a fever and be listless. It is hard to say what he has without an examination from a vet. You can check his body for bite marks bacteria from a bite could cause these symptoms. Also check for swelling around the cat's body.
Good old flu
yellow eyes, fever, death
fever