Critical care policy provides an added cover over a regular health plan in case of critical illnesses like heart attacks, heart surgery, cancer (baring certain kind), organ transplant, stroke, paralysis, burns, and other prelisted illnesses. List of critical illnesses covered may vary for each insurance company.
Critical illness cover can also be taken as a rider along with health insurance and life insurance. In this case, the person insured becomes eligible for increased cover if diagnosed with a critical illness i.e. sum assured for critical illness + sum assured for health insurance.
The disbursement rules may vary. Usually the insured amount is disbursed as a lump sum, the moment an illness is diagnosed. Some companies may disburse it in parts at regular intervals or as the bills are produced up to the sum assured.