For example, the subclass Path of the Barbarian Zealot at the 14th level receives the Rage Beyond Death feature (XGtE, p.11), which prevents you from dying during rabies:
From the 14th level, the divine power that fuels your rage allows you to not suffer fatal blows.
When you are unleashed, having 0 points of life does not make you unconscious. You must still perform lifejackets, and you suffer the normal effects of taking damage at 0 health. However, if you die because your saving throws of death fail, you will not die before the end of your rage and you will die only if you still have 0 life.
What other mechanisms are available to players that can either postpone or cancel death?