Maturing in keg

I have just finished my third brew which I made in time for Christmas, just a simple kit (Yorkshire Bitter ) consisting of the wort and yeast, but I like to add more sugar than the recommended 1kg....this one came out at 5.4 per cent ABV. I use a 5 gallon ( UK ) plastic keg and usually it needs two weeks to mature and go through its "second ferment" before it clears. I am told that maturing in the keg is best done at a cool temperature, but how cool ? My home is quite warm at around 25c and I wondered if I should stand the keg in the refridgerator for 10 days or so.....any comments anyone ?
Mike.

anything under 20C is fine. I would recommend getting it down to 10C or so if you can, it will help the yeast settle faster. A second ferment usually isn't required though, you can just cool your primary down after fermentation is completed. Some styles benefit from secondary ferment, but most of those are sours. Anything that is good to drink right after priming usually doesn't need it.

Good luck!