You can already get small portable air conditioners but until recently, most people with low incomes wouldn't spend £300 on something they might only need for 4

You can already get small portable air conditioners but until recently, most people with low incomes wouldn't spend £300 on something they might only need for 4 weeks per year and needs storing the rest of the time. That might change of course as time goes by. What some people in the UK do is go to local air conditioned public buildings like libraries (which they are welcome to do) and occasionally a large air conditioned store or shopping centre.