The difference for students and instructors between being warm enough and fighting off the cold is night and day: not just comfort-wise, but learning-wise and health-wise.
Every bit of attention spent on ignoring the cold, having to do unrelated exercise in order to warm up rather than spending that time on learning is attention and time wasted.
Warm water allows people to stay in the pool longer. The longer they stay in the pool, the deeper they can go into learning. The deeper they go, the more understanding they reach and the fewer weeks it takes to learn.
Warm water allows people to keep their heat. How many students and instructors get sick after swimming in a cold pool? Do they put 2 and 2 together?
"But it costs too much to heat the pool to 92 degrees."
What is the cost of cold water (80-89) degrees)? If you measure people's resistance to getting into cold water and the losses of learning and comfort, attention, presence, and health caused by cold water, you would likely find it to be higher. We hold that it saves money to teach in warm water.
DO THE RIGHT THING.
"WHAT'S RIGHT CANNOT BE IMPOSSIBLE."
-The movie, Belle
Why give students only some of what they need to learn well the first time? Why not do it right the first time?
"But how will we afford the increase in our electric bill?"
You already pay the power companies to heat your pool to the degree you do. Ask the power companies to donate the power to heat it the last 8-12 degrees. They owe it to the public and to community water safety to make it happen. Radical idea. No reason for it to not work. Let's come together to form a strategy to win this reasonable concession.