Heated blankets

[newmama2022]

Hi I'm currently 19 weeks pregnant (due in April) and I would just like to people's views on heated blankets.
My back has been playing up today and I thought I would use my electric heated blanket on my back. It was on its highest setting, and I had it on for about 40ish minutes.
I'm now worrying as I have looked it up on the internet and apparently this can harm the development of the baby? Is this true?
I check my temperature and it wasn't high so is this ok?
I'm a first time mum, so wasn't aware of the dangers of overheating.
Am I stressing over nothing?

It's only dangerous if you're actually overheating - which you would notice because you'd be light headed or sweating or literally have a fever; that's the point at which risk might come in.
You're not going to give yourself a fever using a heater.
Localised heat on your back is fine - I have bad back pain & midwife actually recommended.