I first discovered that changes in temperature can affect the symptoms of MS when my doctor suggested I try taking a cold shower. I had woken up that morning with a sore throat and a slight fever. Being a doctor myself, I had no one to call for help over something so ordinary as the common cold; but I reached for the phone on that occasion because I could hardly move. It was not until my doctor had explained that my fever was affecting my strength that I recalled a simple lesson I'd learned years before in medical school—namely, that in the old days, the diagnosis of MS was often made by putting the patient in a tub of hot water for 15 minutes and seeing what happened. Marked deterioration was characteristic of MS, just as great improvement could be expected if the hot water were replaced with ice cold water. My cold was like a hot tub: just a 1.5-degree Fahrenheit elevation in body temperature was enough to lay me flat.
So I followed the first part of my doctor's advice—to take Tylenol—and found that my strength gradually returned as my fever receded. Later, when I was feeling better, I followed his second suggestion—to take a long, cool shower—and I was amazed to find that I was still stronger! Although not everyone with MS experiences such a dramatic response to changes in temperature, knowledge of this temperature effect is extremely important for those who do.
From that day on, I have begun each day with a cool shower. At first it was most unpleasant. But I found that starting the shower with tepid water and gradually decreasing the temperature was more comfortable. Because I was a research scientist, my inclination was to measure the effect of what I was doing, and I soon learned to adjust the temperature and duration of my morning shower to consistently reduce my body temperature 0.5 to 1.0°. This small change was enough to increase my strength significantly (measurable in several ways) for a few hours. It was a great boon to my ability to work productively—at least in the mornings. And that's when I had the idea that a midday swim might boost my energy level for the rest of the day.
MS Exercise in a Hydrotherapy Pool. It didn't take me long to realize that I'd been missing something very important—a good way to burn enough calories to keep my weight in check, while experiencing the pleasant psychological effects of a regular exercise regimen.
I was fortunate to be able to build a swimming pool in my backyard, and set about doing so right away. Once my pool was ready, it didn't take me long to determine that if I kept the water at about 78° and swam for 30 minutes, I could drop my temperature by as much as 2.5°! The improvement in my strength was dramatic—much more than after a cool shower. This is most likely due to the fact that swimming is an enjoyable way to spend half an hour, whereas a cool shower is difficult to stretch beyond 15 minutes.
You might wonder why a person could not just stay in a well air-conditioned room—say at about 70°. The answer is that the human body uses a set of regulatory devices to resist decreases in temperature, and as long as the body is surrounded by air (which is a poor conductor of heat), these devices are efficient enough to maintain internal temperature at 98.6 degrees. Water, in contrast to air, is an excellent conductor of heat; when the body is immersed in cool water, the body's regulatory devices can no longer prevent the internal temperature from falling. The speed of temperature fall and the final level attained are determined by how cold the water is and how long the immersion lasts.
(The body's regulatory devices for losing heat are also overwhelmed by water's conductive efficiency. That is why it is dangerous to remain in water that is warmer than about 104°. People with disabling conditions which are ameliorated by heat, such as arthritis, must pay attention to the temperature and duration of their warm hydrotherapy workouts.)
When I began my daily swimming, it was the first really vigorous exercise I had had for a long time. It didn't take me long to realize that I'd been missing something very important—a good way to burn enough calories to keep my weight in check, while experiencing the pleasant psychological effects of a regular exercise regimen. That fall, as I made arrangements to close the pool for the winter I began to dread the prospect of doing without my daily swim until the next spring. That's when I found out about swimming machines.