We asked HaRav Yitzchok Zilberstein, member of Moetzes Gedolei HaTorah: In view of recent tragedies, should every driver buy warning system that will detect the presence of children left alone in a car?
HaRav Zilberstein replied:
In this matter there is an halachic principle that we should even take account of a distant danger. One place this is indicated is in the fact that doctors do not think there is any danger if mohalim will not do metzitza in circumcised babies. Yet the Binyan Tzion (23) writes that one should do metzitza even on Shabbos because who can know if one in a thousand or one in ten thousands will be endangered if it is not done. Do we have to understand why, for such a distant danger, we violate Shabbos? The answer is when you are dealing with massive numbers, if they do not do metzitza for everyone, one in ten thousands will die Rachmono litzlan. When we are ruling for the masses this is considered a danger.
Also in Shabbos (42a) it says that one may douse a fiery piece of metal on Shabbos. The Ran asks: Why do we permit a Torah prohibition even if there is no present danger? He answers that the threat to a large number of people is like sakonas nefoshos. And this is the ruling of the Shulchan Aruch (Orach Chaim 334:27).
Also with a fence around the roof the Torah commanded us to fence any accessible roofs and whoever does not make a fence violates a Torah prohibition of not putting a danger on his property. This is even though the danger is remote and we are not allowed to violate Shabbos to make such a fence. So we see from here that the Torah considers remote dangers.
Therefore we should rule in our case, that even if the danger is remote, since we are dealing with many people, among the entire community there be some who are endangered. This should be considered an actionable danger and everyone should buy such a system, and when getting into a car with a baby should activate it. One who acts with alacrity is praiseworthy.
