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[sb]

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[david_carnell]

Each to their own isn't it. Everyone has different thresholds.

I'd say if you are actually doing lengths you'll be fine but start off with shorter sessions to acclimatise. Cooler water will mean you'll feel more comfortable doing hard swims. Indoor pools in summer feel more like saunas.

The big pool at Crystal Palace is the exception, perhaps due to its size, that always feels refreshing.

[Ladygooner]

It is now 20 degrees so you should be fine. Normally takes a couple of lengths to warm up but much nicer than swimming indoors in the bath that is Fusion East Dulwich

[hc]

I reckon it will be heaven next week in the heatwave

[Lozellen]

I went today in just a cozzie and it was heavenly!