I'm with you, OP (and incidentally also in Liverpool). Cities on the coast in the UK without any proper sea breeze are particularly humid in very hot summers like 2022. I can only think that the people on here saying it was only a few days and it wasn't that bad don't live in a humid or hot part of the country. Or perhaps they don't have to work, or if they do they work in nice conditions in air-conditioned offices with proper break times and flexitime so they can come in early and go early if they want.
I work in a school. July was hell last year. My office is tiny and only has room for 2 desks. THe windows only open a crack. There is no air conditioning. No air flow. We're on a corridor with windows so that we have the sun on our office windows in the morning and then the corridor windows in the afternoon. There is no relief. I take a fan in but it just fans hot air onto me.
I don't do well in heat at all, I have hyperhidrosis (excessive sweating) and humid conditions and temps over about 23 degrees has me sweating excessively (I mean so that my shoes can start rotting after a couple of weeks of it!). Hands slip off my keyboard. I absolutely hate it and am just thankful that we finished at the end of July for a few weeks. Even getting into the car at the end of the working day, I could barely touch the steering wheel.
We flew to West Coast USA a couple of days after breaking up and it was lovely and fresh, even down in Southern California because there was more of a breeze off the ocean. Most places were air conditioned but half the time I was laughing to myself thinking "It's not hot enough here for that - they need it more in England at the moment". I've also holidayed in SW France and while that does get very hot in summer, it is a much drier heat, the humidity is way lower than Liverpool and so sweating really does help you to cool down even if you're active.
Our house faces South and we keep the curtains shut during the day when we are out but still come to a house that is 29 degrees upstairs. And it doesnt' cool down much at all overnight. Maybe about 3 degrees. I would stay up till 2am if I could, when it gets bearable, but when you have to be up at 6.30am to go to work every day then it's just not feasible. School gets shut up overnight so there is no cold night air flowing in to cool the building down slightly.
Most of the plans in our garden didn't grow properly because of the weeks and weeks of drought. They flowered very very early like it was a last hurrah and that was it. Some of them died off completely. I was trying to conserve any rain water in buckets etc and would find dead frogs in them, they were obviously so desperate for water that they just launched themselves in and then couldn't find a way out. I've never seen that before in the 20 years that we've lived here. Like others have said, we mowed the grass at the end of May and then it wasn't needed again till the autumn because it went dormant and brown.
So yes, it was bad in Liverpool, but I was grateful for not living in London as I've done that and in summer being on the tube or in a flat is like nothing else.
The weather WAS vv unusual. Because if you remember we then had weeks upon weeks of rain around September/October time. I mean, constant. Flooding. Then the temperatures dropped and there were quite a few threads on here complaining about mould growth and fungus gnats in their house. Hardly surprising with the weather patterns....
Climate change must be doing this. And that is a scary thought.