The highest temperature I ever saw was in Norfolk, Virginia. “110 degrees fever at home” the triage paperwork said. I looked over the chart to the smiling bouncing toddler trying diligently to dismantle our counter drawer. I asked how the temperature was taken and the grandmother said, “I put my hand on his head and said, ‘Woo, that’s hot! That must be 110!’” She explained smugly, “I had six kids.”

Fever is a common complaint in the ED (Emergency Department… they only call it “ER” on television). Depending on families’ experience, they can either be terrified that their child will have to be poked so much and so many places, or distressed that we’re doing so few tests. Here are some pointers on what to expect if your pediatrician sends you to the emergency department for fever.

The most important thing to know is that fever is a symptom of a disease, and is not a problem by itself. Fever won’t melt brains, and the temperature eventually does stop rising: kids tend to max out at about 106.7°F. About 1 in 20 children between the ages of 1 year and 6 years will have a seizure with a fever. Don’t worry, though… a simple febrile seizure does not cause brain damage. It seems the seizures come from the initial jolt of the first fever, not from how high the temperature goes. When your child has a temperature of 104, there is almost no chance they’ll have a simple fever seizure… they’ve already gotten past that first jolt.

Bacteria and viral illness typically have different fever peaks (viral often higher), and some kids run hotter, some less hot with the same disease. That said, decades of large studies have evaluated children with different heights of fever to determine when the risk of serious bacterial illness is high enough to go ahead and poke them.

Babies younger than six weeks with a rectal temperature of 100.5°F or greater (38°C) will almost always need a spinal tap, a catheterized urine, and a blood culture, and will usually have to stay overnight in a hospital. This is because the risk of a blood or urinary infection is high, up to 1.5% and 8% respectively. While meningitis (infection around the brain) is rare, <0.5%, spinal fluid is checked because meningitis is so devastating and is so easy to treat.

Beyond six weeks, controversy begins. At 3 months, and certainly after 6 the fever can be 102.2 before blood work or urine tests are done in an immunized baby. After a baby is around three months old, doctors can see how well the baby is playing and acting to help decide if the baby needs meningitis tests or not. Girls will still get catheterized urine tests until they are potty trained if their fever gets this high unless another reason for fever is found.

After age two or three years, the height of temperature becomes almost irrelevant and we only do tests based on our exam. If a toddler looks well when her fever is down, no tests may be done. If we hear a pneumonia, we might start antibiotics without an xray. Children this age have a good immune system, so the risk is a lot lower. Plus, they can say, “Hey… this hurts” which makes it much easier to find infection and decide “no tests’.

Your pediatrician is always a best first stop, because they know your child and can watch and wait if there’s an early infection that hasn’t declared itself yet. And, for the record, if a baby is less than 2, go for a thermometer instead of your hand. Woo, that’s hot!

by Dr.Amy Baxter

CEO of MMJ Labs and inventor of Buzzy® and Flippitstm. After graduating from Yale University and Emory Medical School, she completd Pediatrics Residency and a Child Abuse Fellowship at Cincinnati Children's, and Pediatric Emergency Medicine training at Children's Hospital of The King's Daughters in Virginia. Dr. Baxter is director of Emergency Research for Pediatric Emergency Medicine Associates at Children's Healthcare of Atlanta, Scottish Rite, and a Clinical Associate Professor at Medical College of Georgia http://www.buzzy4shots.com