Most pediatricians consider any thermometer reading above 100.4 degrees F a sign of fever, not 98.6 degrees F as you might suspect. (See baby temperature-taking tips.)

That's because "normal" body temperature fluctuates in each of us throughout the day, depending on our age, general health, activity, how much clothing we're wearing, and the time of day. It's usually lower in the morning and higher between late afternoon and early evening.

There's a "normal," healthy temperature range for everyone. For children, it can run between 98.6 degrees F or so and 100.3 degrees F. Accuracy can vary depending on the temperature-taking method you're using, so mention whether you took your baby's temperature rectally or some other way. Your pediatrician probably will ask anyway. (See our buying advice for thermometers.)

For related information, see Swine flu and young children: Prevention at preschool and daycare, and Is the swine flu vaccine safe for children? (with video).

And see Consumer Reports Best Baby Products guide for more child product buying, use, and safety tips, available here or at retailers nationwide.