Parents have been hot to ask me when to worry about their infant or toddler having a fever. Well, let me try to cool down everyone's concern and provide some information on this topic.
First you need to understand that fever is not a disease. It is a symptom that points to an insult - usually infectious-- in your child's body. Second, you need to know that when your body's temperature is elevated, your body is able to kill germs better. So, if fever is a symptom that can help us figure out what is wrong with your child, and germs get killed more quickly if the body's temperature is elevated, is there any reason we cannot simply smile and say in many respects "fever is our friend"?
Yet, when your child is hot and irritable with a fever you may not always view fever as your friend, so let me make some suggestions that might help with this problem.
First, if your child is under a month or two of age and has a temperature of 100 degrees or higher, then please call your baby's doctor to have them examined. The doctor will determine if the baby has a serious problem such as a bacterial infection. He or she will likely recommend further tests often involving checking for infection in their blood, urine, chest, or spinal fluid, and if meningitis is a concern, since fever may be the only clue your baby is seriously ill.
Second, if your child is over a few months of age and has been immunized, then we really don't want to know the the specific height of the fever, just that your child has a fever. We will however, want to know how your infant or toddler is breathing and acting, and whether they are staying hydrated. If you are concerned about any of these things in addition to the fever, your pediatrician will want to see your child no matter what the number is on the thermometer. If they are breathing ok, and appear otherwise well but hot, then keep them hydrated and not too overactive. You can also give them acetaminophen or ibuprofen to reduce their temperature and irritability.