Technion scientists go beyond the thermometer to find the weather's 'real feel'

A new technique improves on the existing wind chill factor estimate by taking into account changes in blood flow to exposed parts of the body.

Snow in Jerusalem (photo credit: MARC ISRAEL SELLEM/THE JERUSALEM POST)
Snow in Jerusalem
(photo credit: MARC ISRAEL SELLEM/THE JERUSALEM POST)
Scientists at Haifa’s Technion- Israel Institute of Technology have developed an innovative and much more accurate approach to measure the “wind chill factor” that estimates how cold it feels outside, rather than just a thermometer reading.
Israelis are well familiar with “heat stress” in the summer, but few know about the wind chill factor used by meteorologists.
It reflects the effects of the wind in making people feel colder than the actual temperature.
As the wind blows faster and harder, the wind chill is lower and can even induce hypothermia.
Emeritus Prof. Avraham Shitzer of the mechanical engineering faculty started to research this matter in the 1940s, and many changes and improvements have occurred since then, he said on Thursday.
“But the calculation of the wind chill factor remains limited because it regards the body as an inanimate object rather than as one with blood flowing through it.”
To solve the problem, his student Yael Ben-Shabbat developed a technique to accurately estimate the wind chill factor and predict its effects on man.
“This is an advanced model for the human body, expressing the behavior and thermic response of the whole body,” Shitzer said. “This takes into account the changes in blood flow to exposed organs and the influence of wearing clothing suitable to the climate,” he continued.
“The influences that cause the loss of warmth to the environment are based under her model on values actually measured in human experiments.”
In addition to the speed of the wind and the temperature and their effects on the body, the Technion formula includes the amount of time to which the body was exposed – which can result in frostbite.
Ben-Shabbat, who received a bachelor’s and a master’s degree in the Technion’s Biomedical Engineering Faculty, is now working in a biotechnology company that is developing life support systems for people suffering from health failure.
Shitzer is still working in bioengineering research, especially the effects of extreme hot and cold temperatures on the human body.