Can using a hot water bottle on your tummy cause a blotchy rash?

What’s the hot water bottle’s exterior covering? The part that touches your skin?

If it’s non-porous (like rubber), then you’ve likely chapped your skin by preventing your sweat from evaporating.

Alternately, you could be sensitive to latex/rubber. I won’t treat you to the alarmist website I took this from, but:
“If you have mild skin reactions from latex, anti-inflammatory medications may help relieve symptoms.”

Personally, I’d just leave it the heck alone for a few days, and hope the rash goes away.

You should be able to buy an electric heating pad or blanket very cheap if you don’t mind disinfecting second-hand!

Yes.
It doesn’t have to be from a “hot water bottle,” specifically, a lot of women get it from using a heating pad. It’s also possible to give yourself a mild burn if it’s too hot. I’ve done that more times than I can count.

I used to get this when I sat too close to the fire when I was younger. I’d get red blotches on my legs.

Yes that’s it!
I put the water bottle directly on my skin and used it quite a lot – as I had gastro so was heating it up almost every 2 hours… lesson learnt eh!
x Thanks guys.

I agree with @ibstubro, you could be allergic. Also when was the last time you sanitized it? Heat cause and the rubber can cause you to sweat and you create a beautiful paradise for bacteria to bloom. It’s warm, wet, dark and cozy. What germ wouldn’t want to live there? We naturally have germs living on our skin and you are creating an incubator for them. And if the rubber pad and your skin isn’t clean before use each time, you just made it all the better.
I once had latex rubber shorts for working out. The first few times, nothing. Then I started to notice I would get a rash. Later I started to get cysts. Even if I washed them before use. I figured it was because no matter how much I cleaned them they just kept creating a nice little heat factory for bacteria.
Maybe you should try using a small cotton cloth between you and the water bottle. If you still break out then you know it’s the heat and not the rubber. If you don’t then you know it was the rubber and not the heat.

@Pandora – so you had to cease and de-cyst….

Well, sure. The heat causes the blood vessels in that area to dilate in an attempt to dissipate the heat.