In his remarks, Trump said his administration will waive certain federal rules to make it easier for more doctors to provide care remotely using video chats and other services.

"I tell you, what they've done with telehealth is incredible," he said, describing the technology as "a fairly new and incredible thing that's happened in the not-so-distant past."

The move is aimed at increasing the number of doctors who can participate in telehealth programs by making it easier for them to practice in states other than where they are licensed.

However, in order to take effect, governors must first use their emergency powers to allow those doctors permission to practice in their states, said Krista Drobac, executive director of the Alliance for Connected Care, a telehealth industry group.

US hospitals and doctors' practices are bracing for a flood of coronavirus patients. For some, the arrival of the virus in the United States has touched off a scramble to adopt virtual medical services.

Health care workers at Massachusetts General Hospital in Boston have lashed iPads to IV poles to create makeshift video portals through which they can communicate with patients in isolation rooms, said Lee Schwamm, vice president for virtual care at Mass General's parent, Partners HealthCare.

George Washington University Hospital in Washington, DC, aims to roll out its telemedicine services in response to the coronavirus as soon as next week, according to Neal Sikka, the university medical school's associate professor of emergency medicine. The hospital plans to use its virtual option to provide doctor guidance on coronavirus symptoms and questions and to help determine whether a patient needs to visit a clinic or emergency room for testing.

It is also looking to serve more of its regular daily patients through telehealth to let them remain protected at home. Plus, it would allow health care workers who have to stay home but aren't very sick to continue providing care, albeit remotely.

Both institutions have dramatically accelerated their plans to deploy virtual medical services, compressing programs that were intended to take years into just a few weeks.

"Right now, I am heads-down, struggling to get 10,000 providers launched" on telehealth services, said Schwamm, referring to physicians, nurse practitioners and physicians' assistants in his network. Within the next month or two, Schwamm hopes that figure will be closer to 50,000 and will include social workers, radiology technicians, respiratory therapists and other specialists.

Telehealth going mainstream

The enormous scope of that effort reflects how telehealth -- initially adopted by wealthier patients as a convenience, and by rural Americans as a critical stop-gap -- is suddenly poised to go more mainstream. Driving that change are three key factors: First is the need to triage the increasing numbers of Americans seeking care in emergency rooms and clinics to get their fevers and coughs checked out. Second is the need to keep coronavirus patients isolated from others, including health care workers themselves. Third is the need to care for existing patients amid a crush of new patients.

"Given the situation, with the concept of social distancing, keeping people away from clinics, we want to keep them at home to keep them healthy," said Sikka. And, said Schwamm, video calls are far more effective than phone calls at determining whether a person is sick enough to warrant a coronavirus test.

As the coronavirus demands more medical resources, many Americans may soon become accustomed to routine interactions with their doctors taking place over text messages, online video or even automated systems.

"It will get more people thinking about alternative ways to communicate with clinicians," said Marilyn Serafini, director of the health project at the Bipartisan Policy Center.

Insurers are also encouraging their policyholders to use telehealth to reduce the virus' spread. Some carriers are giving members extra incentives to dial into their doctors remotely. CVS' Aetna, for instance, is waiving costs for all virtual visits through its covered Teladoc services and in-network providers who offer live video-conferencing for the next three months. The standard co-pay for a general medical visit is about $45.

"Aetna members should use telemedicine as their first line of defense in order to limit potential exposure in physician offices," the insurer said on its website.

Since the insurer announced the waiver last week, members' usage telemedicine services has more than doubled.

Humana and several Blue Cross Blue Shield plans across the country are also offering their members free telehealth visits during the crisis.

A boom in use thanks to coronavirus

Telehealth-focused companies say they, too, have witnessed a boom in the past few weeks that can be traced to the coronavirus. Several have released interactive tools and questionnaires on their websites to help patients diagnose themselves for coronavirus symptoms. Less serious cases end in patients being given instructions to self-isolate; more serious patients may receive a video call and instructions to report for testing.

The telemedicine company AmWell said that usage of its urgent care solutions was 32% higher than expectations on Monday, and 94% above expectations on Thursday. The concierge service OneMedical reported a 51% increase in engagement with its digital platform over the past two weeks compared to the same time last year. And the telehealth company Forward said that usage of its self-diagnosis tool has jumped 400% in the past two days.

"We are seeing a very significant increase in volume coming through our virtual channels," said Andrew Diamond, chief medical officer at OneMedical. "We expect that to continue to increase. So we are flexibly moving more of our patient care resources to that side of our business, with more and more staffing on the virtual side."

OneMedical has adopted an all-hands-on-deck approach, telling its entire clinical staff to take as many virtual calls as they can in between other tasks.

Such a widespread, dramatic shift in the way health care is delivered in wake of the coronavirus is likely to have lasting effects, Sikka said.

"The response to this crisis is probably going to change our perspective on how we do this in the future," he said. "As we ramp this up, I don't anticipate it at all going away."

Restrictions are still in place

But much could depend on the government and insurers. Telemedicine's growth has been hampered by multiple layers of federal and state regulation, which limited it largely to underserved areas or boutique providers. Also, many doctors have been hesitant to treat online, in part because of questions of how they'll get paid.

Along with moves like Aetna's to lower patients' costs and spur increased use of telemedicine, the Trump administration has encouraged use of the technology as a way to blunt the virus' short-term impact on America's health care system. The $8.3 billion congressional emergency aid package temporarily eased certain federal restrictions, allowing some Medicare enrollees nationwide to access telemedicine from their homes, said Drobac. Before, it was available primarily to seniors in rural areas who had to go to a medical facility to connect with a doctor remotely.

Health care providers say those restrictions and insurance policies are what have kept telemedicine from expanding, making the current crisis a potential turning point for broader adoption of the technology.

"If you think about the implications for how COVID-19 will impact the health care workforce, the regular health care system is nowhere close to prepared, and actually will be so overstretched in ways that people don't even imagine today," said Nate Favini, medical lead at Forward. "And so I think the urgency of building technology to help with this is really high."