It is an interesting question though. The principle of indemnity that exists in insurance and is defined as financial compensation, sufficient to place the insured in the same financial position after the loss as he or she enjoyed immediately before the loss occurred. It usually applies to benefit policies such as car, household, motor etc, but Health Insurance is slightly different. They have some of the characteristics of indemnity in that they will pay benefits to the insured for medical treatment received. Where it's different is that you don't receive the financial benefit. It's the hospital that gets the payment. This also insures that the policy of not profiting from insurance is upheld as and the amount paid will never exceed the cost of the treatment.
Where it's interesting though is what if, on an Out-patient claim, each policy entitles you to claim say 50% of your G.P bills. If you claim from 2 policies, technically you are not profiting but simply being 'placed in the same financial position as before'!
The other interesting thing is the principle of contribution which arises when there is more than one valid policy in place. Contribution allows an insurer the right to call upon other insurers liable to the same insured to share the cost of an indemnity payment, but so long as the indemnity is not more that 100% of costs I'm not sure there is an issue!! I'd have to look it up.
I would suggest you thread carefully however. Everyone is entitled to health insurance, regardless of age, sex, health etc. However there is one way you can lose it. Be found guilty of fraud! I will look into it.
Patrick.