The phrase "to put one's life at risk" means to do something that could endanger or threaten one's own life. It refers to taking a chance or engaging in an activity that has potential for danger, harm or loss of life. This expression can be used literally when describing situations where people are actually putting their lives on the line, such as during high-risk rescue missions, military operations, extreme sports or dangerous stunts. It can also be used figuratively to describe any situation that involves taking a big risk with potential consequences, even if those consequences do not involve physical harm.