Unfortunately, I couldn't find specific clips addressing why we wake up when threatened or during a dream about dying. However, common understanding from sleep research indicates that we wake up from dreams, particularly intense ones, because of the body's natural response to threats. This response involves an increase in heart rate, adrenaline, and other physiological changes, which break the paralysis of REM sleep, where most vivid dreaming occurs. REM sleep is known for causing muscle atonia (paralysis) to prevent us from acting out our dreams. Waking up is often a protective mechanism that prevents overstimulation or potential distress from continuing a threatening dream scenario.
If you are interested in more detailed insights from the Huberman Lab, feel free to ask about specific episodes or other related topics.