The only glitch with these industries is their dependence on the global marketplace. There will be significant problems, but these businesses are, and have been, aggressively preparing. The contenders for least prepared sectors are health care, government, transportation, utilities and telephone. All are computer dependent for the delivery of their products and services. There's no way to avoid being impacted by any or all of them.
Health care is one-seventh of our economy.
From diagnostic equipment to delivery of services to payment for service delivered, this sector is guaranteed to be operating in a crisis management mode for some time. HMOs are currently fraught with problems and chaos, but they will soon look like saints as noncompliant computers affect this industry. The second sector of major concern is government. We whine about their inefficiencies without a Y2K problem. It's hard to find any business not dependent upon government in some form.