Included in the obligation to guard oneself is that a person should not guard himself in an exaggerated fashion and should not keep himself back from the service of his Creator by saying “There is danger on the way and a lion in the streets!” and similarly he should not hold himself back from his service of his Creator in order to guard himself in the summer from the heat and in the winter from the cold. Such a person will end up eating until he is more than satisfied and drinking much wine, he will sleep late in the morning and also in the afternoon, he will be pampered and soft and even though he says that he is doing it with the right intentions for the sake of heaven in order to guard his health and welfare, this is only the advice of the evil inclination. It already says that “One who keeps a commandment will not know anything bad!” and Chazal said that “Messengers fulfilling a commandment are not harmed, neither on their way there nor on the way back!”. If any harm should happen to a person by fulfilling a Mitzvah he should believe that which it says in the Talmud that Rav Yosef said “May my portion be amongst those who die on the way to do a Mitzvah!”, as such a death acts as an atonement and he will be invited directly to the life in the next world.
However, all of this applies only in a time and place where danger is not common and it just happened that he was harmed. However, in a place where danger is common we do not apply these rules. Examples of this are ascending a shaky ladder or going in a place where there are hordes of wild animals and highwaymen as in a situation like this he should withdraw his hand and bypass the Mitzvah as the Torah itself says “And you shall live with them!” from which we deduce that one is not supposed to die for them, and one needs just and exact scales to weigh up each and every action. One should nor exaggerate guarding in a place where they said that one should minimize it and conversely one should not minimize guarding when they said that one should maximize it. The general rule is that any harm which can come to a person in a natural way or through a person who chooses to do evil should not rely on a miracle even when on the way to perform a Mitzvah and he should not do anything against the laws of nature. However, on the other hand, he should not worry about any other worries and he should trust in Hashem that nothing bad will happen to him when he is keeping the Mitzvos for the sake of heaven.