Science Mom: F***ing Fevers, How Do They Work?
Fevers aren’t very much fun. They’re miserable, whether you’re a child who doesn’t understand why you feel so poorly or you’re an adult who understands perfectly well but resents it anyway. And of course, when you’re the parent of a sick little one, you want to do whatever you can to make your child feel better. But before you stick a funnel in his mouth to pour liquid Tylenol into, or get him started mainlining Motrin, there are a few facts about what fevers are and how they work that you should be aware of. The gist, however, is this: fevers don’t work exactly how you’ve probably been told they do.
Let’s start with the 98.6ÂºF myth. 98.6Âº is the normal body temperature, so if you stick a thermometer into an orifice and get a readout that doesn’t match those three special digits, it’s time to start worrying. You’re a good mom! That’s what you’re supposed to do! Right? Well, no. 98.6Âº is just the average normal body temp – being concerned that the thermometer says your daughter’s temperature is 99.1Âº is a bit like getting anxious because your family has exactly 2 children instead of 1.9 like the average American family does. And, well, take it away, Morbo:
And not only is 98.6Âº just an average starting point – any given individual’s personal internal thermostat setting varies by around half a degree every day, with lower temperatures in the morning (before the body’s furnace gets going) and warmer ones toward the end of the day (once you’ve had the engine running all morning and afternoon). And of course, the temperature you end up measuring depends on where, exactly, you jam the thermometer. Rectal temperatures measure higher than armpit temperatures, for example, and oral temperatures fall somewhere in between.
What’s more, a kid’s behavior leading up to the thermometer can affect the number you get, too. If he’s recently been sitting next to the humidifier to help with that nasty cough, the evaporating steam might make his forehead feel a bit cooler to your fancy forehead-scanner. Or if he’s been screaming bloody murder ever since your first failed attempt to stealthily jab the thermometer under his armpit, he might feel a bit warmer than usual: that beet-red face means extra blood, and therefore extra heat, lurking just under the skin.
So the numbers aren’t quite as clear-cut as your middle school biology teacher might have led you to believe, but a good guideline on when to talk to your doctor about temperatures obtained the not-so-good old-fashioned rectal way is: 100.4Âº for babies younger than three months, and 102Âº for kids under 3. For your own sad, sickly self, a temperature of 104Âº is a good time to start getting worried as well as sweaty and sniffly.
And even though numbers involve a lot more hand-waving than you might expect, there is one hard-and-fast rule when it comes to fevers: watching your child’s behavior. A kid with a temperature of 102Âº who is crabby but subdued is not the same as a kid with a temperature of 102Âº who is lethargic and who refuses to eat or drink. Numbers are numbers, but a kid who refuses to eat your special homemade macaroni-and-cheese with breadcrumbs and shredded Parmesan on top? That’s serious. (By the way, can I come over for dinner?)
All right, let’s say you have a listless lump of a feverish kiddo on your hands. Now what do you do about it?