Three Hours. Four Hundred Pages.

If John McCain wins in November, he would be the oldest first elected president in U.S. history. This fact has not been entirely lost on voters.

According to a February 2008 poll by the Pew Research Center, 26 percent of registered voters think McCain is too old to be president. This number rises to 32 percent when voters are told that the Arizona senator is currently 71 years old.

In an effort to allay these concerns, the McCain campaign is making it possible for five television networks, three news wires, the Arizona Republic and the Washington Post (as print pool) to review a portion of the presumptive Republican nominee's medical records on Friday.

The medical information being released covers 2000 to the present and will include information about the melanoma which McCain's doctors diagnosed in August 2000, per ABC's Susan Wagner, Bret Hovell, and Justin Anderson.

The medical information is set to be rolled out near Phoenix, Ariz., in three phases on Friday morning beginning at 10:30 am ET:

- Physical inspection of 400 pages of medical records
Written medical summary provided by campaign to all media
Conference call with Mayo Clinic physicians

The conference call, which will be open to any news outlet, takes place at 2:00 pm ET. The McCain campaign is also planning to post a summary on its website.

Joining McCain spokesperson Jill Hazelbaker on Friday's call will be:
-Victor F. Trastek, M.D., CEO, Mayo Clinic Arizona;
-Dr. John D. Eckstein, M.D., Internal Medicine, Mayo Clinic;
-Suzanne M. Connolly, M.D., Dermatology, Mayo Clinic; and
-Michael L. Hinni, M.D., Otolaryngology/Head and Neck Surgery, Mayo Clinic

For those news organizations examining the records in person, the McCain campaign has established certain ground rules:
-Each news outlet will be allowed the same two people in the room for three hours.
-There will be no cell phone or internet use while reviewing the records.
-No cameras will be permitted into the room.
-No photocopying of the records.
-No document can be taken outside of the room.

Dr. Tim Johnson, ABC News' medical editor, weighed in on McCain's health on the Thursday edition of "World News with Charles Gibson."

"The actuarial tables say if you make to 71 in overall good health your life expectancy is about 16 years," said Johnson. "That would be to about to age 87. I think that's surprising to many people."

"Much more difficult to predict," he added, is "any change in mental acuity. At age 71 there's about a 30 percent chance of developing serious memory loss or even dementia. But experts point out that with aging -- maybe some skills such as judgment get better."

"So, Charlie," he concluded, "the old cliché is certainly true in this case. Time will tell"

Here's the one-page medical summary that McCain's campaign released in March 2008:

John McCain has regular medical checkups at the Mayo Clinic in Phoenix, Arizona. His doctors consider him in very good health.

His cardiopulmonary health is excellent.  His blood pressure has always been good.  He had a stress echocardiogram in 2005 which showed excellent heart function and no evidence of myocardial ischemia before or after exercise.  He takes Vytorin for cholesterol, which is now well controlled at 155 (LDL is 83, HDL is 34, and triglycerides is 190).   The Senator maintains a highly active schedule and gets exercise regularly.  In August of 2006 he hiked the Grand Canyon rim to rim and had no cardiopulmonary symptoms.

In August of 2000, Senator McCain had invasive melanoma (Stage IIA) on his left temple, which was 2 cm in diameter - the size of a dime.  The depth was 0.22 cm.  This was fully excised with wide margins (2 cm in each direction).   At the same time, the Senator had a very extensive lymph node dissection to determine whether the small melanoma had spread elsewhere.  This involved an incision down the side of his face and the partial removal of lymph nodes in his neck.  No spread of melanoma was found in any of these locations.  However, this preventative procedure had cosmetic side effects for Senator McCain, including swelling at the site of the incision. Thus, the large scar and attendant swelling that Senator McCain has on the left side of his face is not the result of the melanoma itself, which was small and localized, but rather of the more extensive surgical procedure utilized out of a high degree of caution.

Senator McCain has had several non-melanoma (basal cell and squamous cell) cancers removed, as well as three occurrences of non-invasive (in situ) melanomas, which were removed from his left shoulder in 1993, his left upper arm in 2000, and his nose in 2002.  At no time was there any evidence that these localized melanomas had spread beyond the surface of the skin.  He has had no recurrence of melanoma, and his skin is regularly monitored with an average of 3-4 dermatologic exams per year since 2000.

Senator McCain was a Navy pilot in Vietnam and his plane was shot down over Hanoi in October of 1967.  He broke both arms and a leg after ejecting from his plane.  He was subsequently a prisoner of war in Hanoi for 5.5 years, during which time he was beaten repeatedly and suffered fractures of both shoulders which "healed" without definitive treatment.  He also had numerous rib fractures and a severe injury to his right knee.  When he returned to the USA he had two operative procedures to improve his knee function.  His range of motion of both shoulders is significantly limited, both actively and passively, to only 80 degrees elevation and abduction.  However, his orthopedic injuries do not impact his energy levels or activities.

The Senator currently takes the following medications: Vytorin (for lipid control), baby aspirin, and a multi-vitamin.  On occasion, he takes Claritin or Flonase for allergies.

The kicker:

"I am older than dirt and have more scars than Frankenstein."

--John McCain (numerous)

On the campaign front. . .

BARACK OBAMA

-- 12:30 pm ET: Attends Cuban Independence Day Celebration, Miami, FL

-- 3:30 pm ET: Attends rally with voters, Sunrise, FL

HILLARY CLINTON

-- 2:00 pm ET: Attends event with voters, Brandon, SD

-- 6:30 pm ET: Attends town hall meeting with voters, Brookings, SD

At the White House and Beyond. . .

PRESIDENT BUSH

-- 11:15 am ET: Speaks on World Trade Week, Washington, DC

NATIONAL ASSOCIATION OF REALTORS

-- 10:00 am ET: Releases the April report on existing home sales, Washington, DC

POLITICAL NEWS STORIES ON ABCNEWS.COM

ABC News' Jake Tapper: McCain Rejects Hagee Endorsement and "Crazy" Comments on Holocaust LINK

ABC News' Jack Date, Theresa Cook and Jason Ryan: Rove Subpoenaed in Congressional Probe LINK

ABC News' Brian Ross, Avni Patel and Rehab El-Buri: McCain Pastor: Islam Is a 'Conspiracy of Spiritual Evil' LINK

ABC News' Jake Tapper: Recount Flashbacks LINK

ABC News' Jonathan Karl: Turning Point: The Good News About Iraq LINK

ABC News' Jake Tapper: Democratic Recount Lawyer Takes Umbrage with Clinton Invoking Recount LINK

ABC News' Russell Goldman: Clinton Still in the Game, But Wants Rules Changed LINK

ABC News' Jake Tapper: Ellen Pushes McCain on Same Sex Marriage: "You're No Different Than I Am; Our Love Is the Same" LINK

ABC News' Jan Crawford Greenburg: Obama's "Jewish Problem" LINK

ABC News' Jake Tapper: McCain Slams Obama for Not Serving in Military LINK

ABC News' Rick Klein and Sarah Amos: Bill Clinton: Florida, Michigan Penalty "Appropriate" LINK

ABC News' Jake Tapper: Three F Grades for Our Presidential Contenders LINK

ABC News' Sunlen Miller: Obama Tags in for Kennedy at Commencement Address LINK

ABC News' Jake Tapper: Guam Superdelegate for Clinton LINK

POLITICAL VIDEO ON ABCNEWS.COM

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Obama's Veepstakes Begins?
Dem officials say Sen. Obama is kicking-off a secret search for a running mate. LINK

Progress in Iraq
US commanders offer a cautiously optimistic picture of progress in Iraq. LINK

McCain and the Pastor
ABC's Brian Ross on the controversial pastor who's endorsed John McCain. LINK

McCain vs. Ellen on Gay Marriage
The talk-show host and senator agree to disagree on the issue. LINK

Delegate Math
Sens. Obama and Clinton use different formulas to tally the delegate count. LINK

Kennedy Home from Hospital
The senator sails with family on Cape Cod. LINK

Ted Kennedy at Sea
The senator returned home and headed out on his boat. LINK

Trail Moves Through Florida
Both Democratic presidential candidates make campaign stops in Florida. LINK

Kimmel: Clinton's Sleepy Fan
Senator attracts a range of supporters -- the excited and the tired. LINK

McCain's Pastor Problems
The senator's evangelical preacher is rabidly anti-Muslim. LINK

High Prices and High Profits
What actually results from congressional hearings on high oil prices? LINK

GOP Consultant: 'Some Women Are B----'
Republican advisor says a lot of voters view Clinton as tough and abrasive. LINK