As Donald Trump spends Christmas at his Mar-a-Lago resort in Florida, Americans of goodwill shouldn't begrudge him for taking a break from the crush of transition work. Still, the incoming president needs to consider his vacations carefully and be prepared for intense scrutiny. A president is always on call, and history shows that an absence from the White House can create complications for the administration.
It might seem like in the era before modern communications it was easier for presidents to escape the burdens of the White House. But the president has never been able to fully get away. On April 7, 1793, Secretary of State Thomas Jefferson sent a vacationing President George Washington a letter informing him that war had broken out in Europe, and counseling that the U.S. "take every justifiable measure for preserving our neutrality." Washington did not return to Philadelphia until April 17, whereupon he called a cabinet meeting. Today a 10-day delay in the president's response would be unimaginable.
Theodore Roosevelt's presidency began during a vacation. President William McKinley had been shot in Buffalo, N.Y. but seemed to be stable. So Roosevelt, the vice president, went on a family trip to the Adirondacks. When he learned that McKinley's condition had taken a turn for the worse, Roosevelt set out again for Buffalo, but McKinley died during the return journey. Roosevelt took the oath of office shortly after arriving.
Perhaps influenced by this experience, President Roosevelt transformed the concept of the presidential vacation. In July 1902, he established a remote White House in his Long Island vacation home, Sagamore Hill. The invention of the telephone made this more practical, and he brought a robust staff instead of the customary single clerk. The combination meant that the president no longer had to step out of his duties while away from Washington.
Yet presidential vacations were still not risk-free endeavors. Lyndon Johnson was away at his ranch in Texas in 1965 during the Watts riots in Los Angeles. An aide, Joseph Califano, frantically tried to reach Johnson to no avail. This dilatory response set a bad precedent. From then on race riots would plague Johnson—and the country—every summer of his presidency.
A vacation can't shield the president from bad news. In 1998 President Bill Clinton went to Martha's Vineyard right after the speech in which he admitted to an inappropriate relationship with Monica Lewinsky. The decision hurt him, as press aide Joe Lockhart recollected in an interview: "All of a sudden, he didn't have any way to show that he was doing the people's business . . . and the Democratic senators started getting a little squishy." Mr. Clinton did secure the Democratic support he needed to avoid conviction in the Senate, but he was unable to prevent being impeached by the House.
In 2005 George W. Bush was on vacation in Crawford, Texas, when Hurricane Katrina hit. Mr. Bush ended up being blamed for the ineffective response to the storm, which killed more than 1,800 people and caused nearly $150 billion in damage. Not all the attacks were fair, but Mr. Bush acknowledged in his memoir one of his mistakes was not returning from vacation sooner.
All that said, time off is important for the president's health. President James K. Polk frowned upon vacations. "No President who performs his duties faithfully and conscientiously," he wrote in his diary in 1848, "can have any leisure." Consequently, he expected "to remain constantly in Washington." In four years as president he was away from the White House for only six weeks. And workweeks for Polk typically lasted a full seven days. All that took its toll: He died only four months after leaving the White House. Many historians surmise he was killed by exhaustion.
In the modern era, presidents can go just about anywhere and remain in contact. But world events now happen faster than they used to, and Americans expect a response from their president, vacationing or not. As Mr. Trump prepares to take his first break since winning the election last month, he should be mindful of his predecessors' experiences and stay alert even when away from Washington.
Mr. Troy, a former deputy secretary of health and human services, is the author of "Shall We Wake the President? Two Centuries of Disaster Management from the Oval Office," out in September 2016 from Lyons Press.