Hi
Bednbones,
I live here, in the UK. Let me make your trip easier.
1. The power transformer 'brick' that you have which sits between the wall socket and the DreamStation automatically adjusts to UK voltage so you don't need an adapter for that. Which leaves the wall socket. And the easist and most secure way to plug into a UK socket on your trip is if you buy one of these from Amazon:
https://www.amazon.com/InstallerParts-P ... 2TMHPAF685
2. Wrt surge protection, the power supply in the UK is very stable. Added to that, the 13-amp plug indicated above actually has a fuse inside it. And there is another layer of protection in most homes nowadays – between the wall socket and the mains there is a 'trip-switch' fuse. Reacts very quickly to short circuits and surges on the rare occasion they occur.
3. As several people have said, distilled water isn't an absolute necessity. It's more of a convenience. And London tap water is safe to drink, and will do.
But you might ask your friends to get you some Sainsbury's Still Scottish Mountain Water (45 pence for a 2-litre bottle). It's the next best thing to safe distilled water, and it's easy to get. Sainsbury's is a national chain of supermarkets and has stores everywhere.
4. Please don't be tempted by the stuff labelled 'distilled water' in gas stations and in motor-vehicle-accessories stores (for example, in a national chain called Halfords). It isn't guaranteed to be sterile. And medically-guaranteed distilled water is only available from pharmacists – and is very, very expensive.
5. When it's time to cross a road with vehicle traffic on it, we don't have jay-walking laws. But we do have people driving on 'the other side' of the road. So when you're about to cross the road, first look right, then left, then right again ...