Is Fever Dangerous to My Infant

What's the Issue?

Almost all infants will have at least one episode of fever by their first birthdays. Some babies will have many. Fever is defined by most pediatricians as any temperature (rectal is still the gold standard for infants) at or above 100.5 (38 C). A febrile (what doctors call "feverish") infant is cranky, harder to console than usual, and naturally worrisome to parents. 

Most parents I talk to are either worried about serious bacterial illness or that the height of the fever is dangerous to their baby. "Will my baby have a seizure?" "Will my baby suffer brain damage?" The short answer is this: fevers are short-lived, normal, and totally benign.

What Parents Can Do

Stay calm. Fever is a sign that your child is fighting an infection, but also a sign that your baby's immune defenses are working well. When a body senses an "invader," (most likely a virus) it cranks up the thermostat so that the invader can be killed. Your body (and your infant's body) knows that viruses and bacteria don't exist well at high temperatures. Thus, the brain (specifically, the hypothalamus) raises the temperature in an effort to protect your infant from infection. The bottom line: fever is a good thing! 

So what do you do when you are at Grandma's house and the temperature is too high? Well, if you're like me, you sneak over to the thermostat and turn it down a degree or two. (Don't tell my grandma.) That's what acetaminophen, the generic name for infant Tylenol, does. (Generic is just as effective as the more costly name brand, by the way.) Acetaminophen directly affects the brain's thermostat to lower your infant's temperature an average of one degree. That one degree doesn't seem like much, but it is certainly enough to take the edge off and make your infant more comfortable, perhaps allowing her to get back to sleep. (Use this acetaminophen dosage chart.) 

What should you NOT do for a febrile infant?

• Do not put your baby in a tepid bath. Your goal is to provide comfort measures, and nothing makes a baby more irritable than a tepid bath in the middle of the night. Would it make you more comfortable?
• Don't go to the ER. The doctor will yawn and send you home after a lengthy wait. Even worse, the doctor might feel obliged to do a set of well-meaning but unnecessary tests. (Of course, there are other symptoms that can go hand-in-hand with fever and do necessitate emergency care. See tips on when to call your pediatrician below.)
• Don't give more than the recommended dose of Tylenol or give it more often than the recommended frequency. More is NOT better. In fact, too much Tylenol is far more dangerous than the fever itself: Tylenol is best dosed by weight, not by age. So if you have a 40-pound two-year-old, he should be dosed based on weight, or as if he were four years old. (Click here to read a 2007 Tylenol recall release.)
• And most importantly, don't panic. Fevers go down as quickly and dramatically as they go up.

Besides infant Tylenol, what CAN make babies with fever more comfortable?

• Consider offering ibuprofen, at the recommended dose for Baby's weight, if Tylenol hasn't worked within 45 minutes (the typical time is takes Tylenol to start to work). Click here for an ibuprofen dosage chart.)
• Offer small amounts of fluid frequently to avoid dehydration, as fever can dehydrate an infant quickly.
• Use any comfort measure that seems to work: extra cuddling, a cool cloth on the forehead or the back of the neck, fewer layers of clothes, more frequent nursing, etc.

DO call your pediatrician if your infant is:

• Hard to console, despite having waited for a correct dose of Tylenol to kick in.
• Dehydrated—she has no urine output for more than six hours.
• Having any breathing difficulties, such as audible wheezing, struggling to get air in or breathing more than 60 times in a minute. (Click here to calculate your child's respiratory rate.)