What's considered a fever?

[CaparaAlecha]

My little one has a fever. She was super hot last night. I took temp under her arm as recommended, 38.5. Not so high but she felt very hot.

This morning she still felt a bit warm, took her temp under arm again and only 37.4.

According to NHS, this isnt a fever. Obviously i kept her home anyhow but i was wondering that surely the temperature varies by how you take it. Isnt underarm lower than oral which is lower than rectal? The nhs website doesn't differentiate but surely 37.4 by underarm is a fever when oral wouldn't be? Am i missing something?

[BoobleMcB]

The idea with most thermometers is that they give you a reading of the core temperature. So it doesn't matter where you take it.

We always say don't treat a temp UNDER 38 unless there is other indication. Even above 38, if they're otherwise ok (I appreciate they're not well, but if they're coping) don't rush to treat. A temp is the body's natural way of fighting infection

[CaparaAlecha]

I always understood that under arm is one degree lower than oral.
I just did a quick test on myself. 36 underarm and 36.8 orally. And that totally fits with how hot she has been feeling, she clearly has a low grade fever even though the underarm temp is showing not.

I wasnt asking becuase i want to lower the fever, I'm completely aware of the advice. I was just wondering how a fever is only considered from 38 degrees regardless of whether it's underarm or oral. The advice seems misleading to me. Based on that advice, i may have sent her to nursery.

[CaparaAlecha]

I meant the advice on what's considered a fever is misleading, not whether medicine to lower a fever should be given out of hand, totally on board with that!

[WolandWat]

Yes, the NHS online advice doesn't seem to take into account that underarm comes out lower, even through they recommend taking temperature under the arm.

On the guidance for the digital thermometer I have, I think it says something like 37.2 under the arm is raised temperature. That fits for my kids, whose normal underarm temp is more like 36.

[Tinseltower]

Add a degree for underarm.

[Tinseltower]

The more advanced thermometers (like hospitals) calibrate themselves according to where you take it. There’s an option on the thermometer to select the site that’s it’s being taken from.

[Moonflower12]

Tympanic ones seem to give the most accurate reading imo. I've spent a lot of my life taking temperatures both at home and at work.