Rabbi Dov Brezak,
Principal and Director, Talmud Torah Ezrat Torah, Yerushalayim
T(wc) =0. 0817(3. 71V**0.5+5.81-0. 25V)(T-91. 4)=91. 4.
This is the old formula, which is actually outdated. The new formula is: 35.74+0. 6215T-35. 75V(**0. 16)+0. 4275TV(**0. 16).
Despite the formula's practicality, one expert predicts that the public may not embrace the new formula. "Everyone hates change, and some people are not going to like it," he said.
Before I reveal the identity of these formulas, allow me to explain how I became interested in this subject altogether.
Many years ago, when I had just become principal, I went to Harav Wolbe, shlita, to seek his advice.
"What is my foremost responsibility as principal?" I asked. I was not expecting the answer I received.
"You must be careful to take proper care of your health," Rav Wolbe said.
I cannot say that I have properly heeded his words, but, in retrospect, I can say that he was right on the mark. Everyone, especially those in tension-filled situations or those overburdened with major responsibilities, has a special obligation to protect his health. Those in public positions have an even greater responsibility to do so for they must remain healthy to continue their public service.
It is this obligation that has forced many of our gedolim (great sages) to involve themselves in physical exercise, in various forms and fashions. I cannot forget the time I saw Harav Shach, ztz"l, at the beach in Netanya many years ago. He was helped into the water by two young men, one on each side, and remained there for a while. If you are ever in Israel in the summer, it is certainly worthwhile to go to the beach at Netanya. You will come across many rabbis and roshei (heads of) yeshiva, gathering strength at the sea for the coming year.
This phenomenon is not unique to Eretz Yisrael. A friend once went swimming in the States only to meet up with a renowned posek and talmid chacham (judge and wise man) who was also swimming there for health reasons.
At this stage in my life, and with the rigorous schedule I keep, my doctor told me I must engage in some sort of physical exercise on an ongoing basis. I decided upon swimming as my form of hishtadlus (effort), feeling myself in good company as I think of the gedolim mentioned above.
On one of my trips to the pool, I noticed a vent blowing hot air in the changing room. "That's appropriate," I thought to myself. "People who feel chilled coming out of the pool can warm up." When I came out of the pool, I went over to stand near the vent, expecting to be warmed by the hot air flowing out.
Much to my dismay (and surprise), the vent was now emitting cold air. How strange. Before people entered the pool, it blew hot air, and when people left the pool, it blew cold air. Wouldn't the opposite be more appropriate?
I remained surprised and puzzled by the pool administrators' strange choice.
One of my next visits to the pool left me even more in the dark. Once again, upon entering the changing room I noticed that the vent was blowing hot air.
Yet as I was standing there feeling the flow of hot air, another person who had just finished swimming came over and began to complain about the cold air blowing from the vent.
"How is this possible?" I wondered. Both hot and cold air was blowing out of the same vent at the same time. How did the vent know who got the hot air and who the cold?
I expressed my amazement to one of the other people in the locker room. He smiled. "It's the wind chill factor."
This fellow was a physics major, and he began to explain the workings of this strange phenomena. Although he seemed to understand what he was saying, I cannot say I came away with the same clarity.
His explanation went something like this: When a person is wet, the heat blown by the vent works to evaporate the water. Because the heat is used up in this activity, only cold air remains. On the other hand, the person entering the pool is dry, so no heat gets used up. Therefore, the air coming from the vent remains hot.
What this has to do with the wind chill factor still was not clear to me, and so I did some research. What I came up with was that when wind blows on a person, it dissipates his body heat, making his body feel colder.
Most people think that the wind chill factor is a figment of the person's imagination. He feels cold because the wind is blowing. But in reality, the wind actually causes body heat to dissipate and his body does actually become colder, though the air temperature remains constant. Thus, when the wind blows strongly it can even cause water in a glass to feel colder than the actual temperature.
The formulas given at the beginning of this article are two separate ways to calculate wind chill factor, the old way and the new way.
You may find this lesson in physics to be rather lacking, and I agree except that there is a very powerful chinuch (child-rearing) lesson to be learned here.
We see that though hot air is being blown out of the vent, the recipient may actually experience it as cold air, depending on other environmental factors.
We may feel we are being a good parent because of the effort we put forth. Yet the message of the pool vent is that it is not enough to look at what we are doing; we must focus on the person on the receiving end - in this case our child. We must look at the results our efforts are producing and to the impressions formed on the recipient's heart as a result of what we are doing.
Reprinted from "Practical Chinuch in Our Turbulent Times", Yated Ne'eman , 5-23-02.
