VeNiShmartem Meod LeNafshotheichem (Devarim 4:15), the Mitzvah of self-preservation - requiring that we guard our health - sounds rather proactive. However, it is written with the word ShMR, to "guard", which is seen in the Mitzvah to guard Shabbath as the word which gives force to the negative commandment - the prohibition - not to violate the laws of the Sabbath, as distinct from the positive commanment to "remember" the Sabbath.
Does this mean that VeNiShmartem is a negative Mitzvah, a prohibition? If so, does every unsafe action or unhealthy indulgence constitute a violation? And if so, would it follow that it should be punishable by Beith Din with proper warning and witnesses, etc.?