Critical illness cover pays a nontaxable payment if you are diagnosed with a defined essential sickness throughout the policy term.
Provided you retain paying your premiums, you should be covered throughout the term. Once the policy term ends, all protection stops. When you put off a policy you'll be able to decide however long it'll last e.g. till your children have full-grown up, or till the mortgage is paid off. Critical illness cover is usually out there as a combined policy with term insurance. In these instances, you'll be able to usually only claim once.