You’re definitely not the only hot water bottle fan here. You’re in good company!
You’re right in that an electric blanket goes underneath the bedsheets but a heated blanket is literally like a blanket that you drape over yourself almost like a shawl. So, you’re effectively wearing it and it’s heated up so you can stay in your own cocoon of warmth without having to whack the heating on too high or even often. They’re very economical to run costing between 3 and 4p an hour.
I’m somebody who feels the cold far too easily so this is a must buy for me for Winter. The lovely @anon6309382 has got me fully converted!
BTW, if you’re interested in heated stuff beyond blankets, there also are heated clothing like thermals / long underwear, sweaters, hoodies, jackets, etc. For walking out, there are heated shoes or boots. And you can buy pocket warmers that are one-use bags or rechargeable pods.
There recently was a funny social media post about a sports fan who was eating a jacket potato in a freezing stadium during a game. Many folks don’t know that in olden days, people often roasted potatoes and stuffed them in their pockets when venturing out — lunch and a hand warmer in one.
I read about the potatoes in books about pioneers and such as a kid. Once, as an adult, I donated a case of hand warmers to folks who were on strike, marching outdoors. I thought about ordering a case of jacket potatoes from a restaurant instead, but didn’t know whether the strikers would just think I had weirdly ordered only potatoes for their lunch.
I’m on a sit just now in Germany and they have one on the sofa for the cat. It’s lovely and cosy. , I will definitely be getting one. I too never go anywhere without my hot water bottle
@Chatsetchiens@CreatureCuddler@DianeS thank you all for your explanations. I figured there must be a difference as I cannot imagine a heavy electric blanket (as I know them from my grandparents!!) wrapped around me. I’m delighted to learn they come in lightweight blanket form too!!
Thanks @CreatureCuddler for the link- i’ll check it out. @Maggie8K thanks for all the other suggestions! I’m actually a tropical babe & don’t plan on acclimatising TOO much to cold weather although we have just confirmed a winter (cat) sit in the UK so I will bear all that in mind!!
@DianeS I have seen hot water bottles where you slot your feet in but not actual electric foot warmers- sounds super cosy!
I have a wonderful pair of sheepskin UGG boots (a gift from a host!!) I use them exclusively indoors- fabulous, especially on cold stone floors!
and maybe one for the cat too 
