Where I work, if you get sick and need to take an extended leave, first you use up your vacation and sick leave. Once you have exhausted both of these then you must go begging to your co-workers for 'vacation donation'. Your co-workers can each donate up to 12 hours of their accrued vacation time to you. Once this runs out, you lose your health insurance. Just when you need it the most, it's gone. How fair is that?
Here is an interesting link that explains who the uninsured are. You might be surprised to learn that most of them hold down a job.
And here is another interesting concept; insurance for in case you lose your health insurance.