AIBU to not trust thermometer reading?

[Toadhall44]

Hi,

I have a 6 week old baby and her base line temp is always in the low 37's. I have been told that 38 is a medical emergency and anything above 37.5 is a low grade fever. She has had a cold for over a week and hasn't been herself and so was asked to make sure she does not develop a fever. However, even the doctor said that my baby is unusually warm to touch but that her temp is in normal range so understood why I was struggling to gage if she had a fever or not by touch alone.
In the UK we are told to use underarm thermeters and that's what all doctors use so that's what I have been using.

I use the tommee tippee under arm one - this morning, one temp was 37.7 which is a low-grade temp.

I then took it another 2 times (once under each arm) after letting her rest a little to see if her temp decreased as she had been crying a little before temp was taken and one side was 37.5 and the other in normal range.

I then used a different thermeter (TempaDots) under each arm and the readings were all normal range.

AIBU to trust that the higher reading was false? How can you get a false higher reading? I was told to trust the higher temp as you can't get false highs. I'm done taking her temp until I speak to HV later today and will just track her behaviour.

Does anyone else have experience of this?

Out of 5 readings only one was slightly above average. Even if the first reading was correct a temp of 37.7 is barely out of range. I understand you’re concerned about your baby but temps can happen with mild illnesses and it’s part of her body’s way of fighting it off so try not to panic.

is she otherwise well, eating normally and having usual nappies, sleeping and enjoying cuddles? If so just keep doing what you’re doing. Also, how many layers have you got her in, she may be overheating if you’ve got her too wrapped up. Rule of thumb is one more layer than you have on so if you’re comfortable in a t-shirt she only needs a long sleeve sleep suit, if you are chilly and put a jumper on put a blanket or thicker sleep suit on her. HTH.

Hi @Toadhall44 , I remember being so concerned and not trusting thermometers when DS was 6 weeks old with covid. Could you perhaps get another under arm digital thermometer just so you're completely sure? The nurse at my GP practice recommended the Braun Age Precision thermometer as being very reliable. Would the GP see her just for peace of mind as she's so young? You're right that 38 degrees needs a trip to A&E with a baby so young.

@wordywitch just a side note, it's not normal for a 6 week old to spike a fever. So while yes it's part of fighting off illness in a baby over 3 months, it is something to worry about in a baby so young because they often don't have the ability to fight off illness.

It could simply be that the way she was lying she was warmer, but you lifting arms, undressing to get access to her armpit made the second reading cooler.

That said, as someone who has to monitor their temperature quite regularly due to medication, if she is normally in the low 37s, I wouldn’t give a 37.7 a second thought. Obviously I am not a 6 week old but I am immunocompromised, and my normal temp is low to mid 36 on my thermometer. If it’s 37.5, I in a fever is coming. It’s very likely your thermometers are differently calibrated and she runs a little warm. I wouldn’t do anything about a temperature below 38 anyway though.

@remaininghopeful23 A temp over 38 would be a concern, yes, but one reading out of 5 being 37.7 is not necessarily a concern UNLESS the baby is not eating or passing urine and stool normally, is lethargic or excessively sleepy, crying more than normal, has a rash, etc.. That’s why I was suggesting the OP take the whole picture into account before deciding whether her baby requires medical attention or not.

@wordywitch No no I totally get that and you're absolutely sensibly mentioning taking the whole picture into account. Totally agree with you! Just when you said "temps can happen with mild illnesses and it’s part of her body’s way of fighting it off so try not to panic" I took it to mean don't worry if she does have an actual fever. At 6 weeks old I would be worried so just wanted to clarify for OPs sake.

I apologise, I was unclear. I meant for a temp that falls within that ‘grey area’ of 37.5 to 37.9, to assess the whole picture and retake it (as OP did) before deciding whether to seek medical care.