Hi
Same problem here but opposite season, now into Autumn and get cold in the evening so slip into nice warm bed (thanks to electric blanket) but then have to turn if off quickly before getting too hot. The last week or so through the night it's been duvet on, duvet off which is disturbing sleep. It was actually better when it was super hot (mid-late 20's at night!) and just went to bed with a sheet over me. Luckily I'm down to one proper hot flush at night with trip to bathroom now (around that dreaded 2-3 am) but the constant feeling hot then very cold is driving me nuts!
Unfortunately here in Oz we don't have the lovely UK central heating which at least keeps temps even. We have this stupid warm air heating, costs a fortune to run and is great whilst it's on but then once it's gone off it's cold again, never warms the air up. Therefore it's really not worth having it on at night at all, so when body temp drops around 6am you really feel it, get snuggled down in duvet and then half an hour later flinging it off again - arghhhhh!
Although I think with the weather the UK keeps getting, you'll be lucky to get any constant temperatures for it to settle down!