High temperatures do not mean you can't brew, it means you can't control the taste. Changing yeast will change the taste, so you can't experiment in hot weather without a brew fridge, because you don't know if the change in taste is due to temperature or some other change.
Early days I would try slight changes to a beer kit to try to improve it, more sugar, less sugar, licorice root, orange juice and all sorts to try and get the standard can to produce a better brew, the problem is I would get a good brew, but then could not repeat it.
I did not move to a brew fridge to brew in the summer, I got it so I could move brewing out of the kitchen into the garage, the problem with the fridge is it does not allow heat to escape, so once you start using it you need the motor to run until ambulant drops to around 14 degs. I had all sorts of ideas about leaving door open and only using a heater, but it did not work, once you move then the refrigeration is used 7 months of the year even though without putting it in the box you could with same yeast brew for 9 months without the temperature of brew changing.
However once you do move then you can start experimenting with the brew and get consistent results, including the time taken to do a brew, no longer are you reading the hydrometer every day, if the brew took 21 days last time, it will take 21 days this time. It makes brewing easy, I had four days when I looked at the brew, day one all stuff mixed and brew started in freezer, day two was 6 days latter when the brew was moved from freezer to fridge, day 3 was next day when the brew had settled again racking to clean fermenter, and last day was after 20 days bottling it. With a fridge/freezer I found the fridge does not cool, so start in freezer at say 19 deg, once first 6 days over want temperature to raise slightly so moved to fridge, set at 22 degs, since most fermenting finished at this point not longer needed refrigeration and the height of the fridge allowed racking, on day six once moved I could start another brew, actually day seven since only two fermenters so once racked I could clean the fermenter and start another brew. So average was a brew every 7 days.
But all this did not make the brew better, is was consistent I knew what it would turn out like, but not necessary better. If you move to a yeast able to take higher temperatures, and use it all year round, you can still get the brew to a set temperature, and get consistent results. Having temperature control is the important thing, it does not really matter if you keep the brew at 19 degs or 26 degs, assuming a yeast to suit those temperatures, it's the keeping the temperature the same each time so you can experiment with other things. It is pointless using some honey instead of sugar if you also change the temperature, as you will not know if the change in taste is due to honey or temperature.
Without the refrigeration I never had a beer I could not drink, some brews were better than others, but all drinkable. Yes those brews made in winter were better than those made in the summer, but I still drunk the summer brew, and if you get the brew started when it is cool then if the temperature raises after not really a problem, as long as you don't start a brew when it's hot.
