If one does not have a living will there is a real risk that life savings will be severely reduced.
A living will, also known as an advanced medical directive, is important when it comes to planning for end-of-life care but, if not done well, can be ineffective as Wealth Management discusses in "What Advisors Need to Know about Living Wills."
You also need to let other people know you have a living will. If you stick it in a desk drawer without telling anyone, then no one will know to give it to medical professionals at the appropriate time.
Finally, every state has its own laws concerning living wills. In some states you must use official forms. In every state, even if official forms are not required, specific language must be included in a valid living will document.
An estate planning attorney can be helpful in guiding you in creating a plan that includes an advanced medical directive that fits your unique circumstances.
Reference: Wealth Management (Sept. 27, 2016) "What Advisors Need to Know about Living Wills."