Holt had been in reasonably good health throughout his life, although he had a family history of premature death – his father had died at the age of 59 and his older brother at the age of 57.
Холт отличался крепким здоровьем, хотя некоторые члены семьи умирали преждевременно — его отец скончался в возрасте 59 лет, а старший брат — в 57 лет.