Canadian passport does not give you free healthcare; it is completely unconnected with citizenship.

Health care, like most thing, is the responsibility of the provincial governments. You have to be a resident of a province for a period of time, usually 6 months, to get free healthcare in that province. Provinces do cover out of province travel and some limited international travel though usually not the US -- but that all varies by province.

If you are a non-resident Canadian citizen, you will not be covered and have to pay full even if you are treated in Canada. For example, if you move to the Bay area for work, go home at christmas and break your leg, you will be out of pocket the total costs.

However, if you a resident non-citizen (i.e., PR, TFW, Student), you will be covered after your residency is established.