"A Fever is the body's natural response it's usually due to some infection which causes chemical mediators to increase and fight it," explains Andrea McCoy, M.D., director of primary care at Temple University Children's Medical Center in Philadelphia. "Reducing a fever slows this process down." The low-grade fever If your baby has a fever of 99? F to 100? F, ride it out. "The [low-grade] fever itself isn't harmful; if there are no symptoms like crying or inability to relax, you don't have to try to reduce it," McCoy says.
A temperature of 101? F or higher might warrant giving medication such as acetaminophen for discomfort; also give fluids. However, treating a child for a fever can create problems. For example, once a child begins to feel better, it can be difficult to assess how sick she actually is. Wait and watch the fever While treating a temperature of 101? F or higher is well-advised, many parents will administer the medicine when the mercury first begins to rise.
This is a mistake; it's better to wait and see what happens. Roughly three-fourths of all baby fevers stem from some sort of virus (such as the flu), which usually goes away on its own, says Ken Jordan, M.D., a pediatrician at Guilford Child Health in Greensboro, N.C. "But fevers can also come from urinary-tract or other bacterial infections," he says, "and those need to be evaluated and treated." Any fever of 101? F or higher for more than two days warrants a call to the doctor.
Most doctors agree that fevers are most serious in babies younger than 2 months, so consult your physician immediately if a very young baby's rectal temperature hits 100.4? F. It's also important to watch for accompanying signs in older babies. If your child is unresponsive, won't eat or drink, or seems to be in real pain, contact your doctor regardless of the temperature.