Can you believe it? I went swimming last evening in an outdoor pool at Exeter Country Club! We recently joined in order to improve our winter fitness levels and I discovered that this winter the outdoor pool is being kept open and, most important, heated! It turns out that a lot of members like to use the outdoor pool and the cost of heating is no more than shutting the pool down for the winter. Perhaps one reason members like the outdoor pool is that kids won't go near it!
While the water is not as hot as the indoor pool (where you can work up a real sweat by not doing anything) there was some steam rising into the 7ºC atmosphere. So it was comfortable for a good workout. Last time I swam outdoors in winter at night was at Banff Springs Hotel, Canada when it was -5ºC. But there the thermal water was too hot to swim in!