I'm thinking a 72 year old with multiple bouts of cancer and a history of high cholesterol, along with multiple older injuries might not be able to qualify.
Then there is this from political wire:
Will McCain Die in Office?
Politico looks at the likelihood of Sen. John McCain living out his presidency, if elected this November.
"It's a macabre point to raise on the night when Palin will speak to the convention here -- but a look at the actuarial tables insurance companies use to evaluate customers shows that it's not an irrelevant one. According to these statistics, there is a roughly 1 in 3 chance that a 72-year-old man will not reach the age of 80, which is how old McCain would be at the end of a second presidential term. And that doesn't factor in individual medical history, such as McCain's battles with potentially lethal skin cancer."
"The odds of a 72-year-old man living four more years, or one full White House term, are better. But for a man who has lived 72 years and 67 days (McCain's age on Election Day this year), there is between a 14.2 and 15.1 percent chance of dying before Inauguration Day 2013... Going by the Social Security Administration's tables, that's nearly ten times the likelihood that a man aged 47 years and 92 days (Barack Obama's age on Election Day this year) will die before Jan. 20, 2013."
http://politicalwire.com/archives/2008/09/03/will_mccain_die_in_office.html