Many people take out life assurance to ensure their dependants receive a lump sum in the event of their untimely death. But considerably fewer families are insured against dire financial consequences which can follow the breadwinner's survival of a critical illness.

We plan for death, not for sickness. Each year many people are struck down with a serious illness at the prime of their working life.

The average age of women who made claims against critical illness policies at Irish Life in 1996 was as young as 36 years. For men, the average age of claimants was just 38 years, while the average age for both sexes was 37 years.

Of 226 admitted or pending serious illness claims in 1996 to Irish Life - one of the major players in the critical illness market - some 11 per cent related to claimants who were younger than 30.

Almost a quarter were aged between 30 and 39. Forty-seven per cent were aged 40 to 49, while only 17 per cent were over 50.

Some 72 per cent of women claimants had cancer; 11 per cent had multiple sclerosis; 4 per cent had suffered a heart attack while 13 per cent had conditions such as brain tumours, strokes or the loss of speech.

The breakdown for male claimants was: 37 per cent had cancer; 34 per cent suffered a heart attack; 11 per cent received a coronary artery bypass graft; 6 per cent had a stroke; 3 per cent had multiple sclerosis; 2 per cent had a benign brain tumour, and 7 per cent had other conditions.

Successful claims for serious illness cover in 1996 paid by Irish Life - of 17 samples published - ranged from £15,000 to £120,000. The average claim paid from these was just more than £43,000.

Just 28 per cent of small business owners are covered by critical illness insurance, according to Mr Pat Delaney of the Small Firms Association.

Mr Delaney says the SFA recommends it to all its members and he stresses the need to take out cover while you're well: "If you become critically ill it'll be very difficult to get cover in the future."

Figure out how much cover you need - rather than how much a salesman says you need. There's little point in insuring yourself for £200,000 if £100,000 would cover your risk. Bear in mind, too, that premiums are cheaper on a policy without any surrender value.

To insure a 35-year-old male nonsmoker for £100,000 over 20 years on a critical illness policy with an encashment value and optional benefits could cost close to £50 per month. But a policy for the same person and term for £50,000 without a surrender value - but which includes a benefit of up to £20,000 in the event of his child suffering a designated serious illness - costs only about £17 monthly.

Decide how much you'd need to pay off your mortgage and any other personal or business loans you owe. Build into the equation your loss of earnings and possible loss of livelihood.

It's essential you read the fine print of any serious illness protection policy. For example, some policies exclude benefit if conditions such as coma, severe burns, paralysis or major head trauma arise due to self-inflicted injury. Some exclude conditions caused as a result of alcohol or drug abuse, hazardous pursuits, deliberate neglect of health or the failure to follow medical advice.

Others exclude benefit in the presence of HIV/AIDS, or if a serious condition was caused by war or a riot.

Critical illness benefit pays a specific benefit for a specific illness. If you don't get the illness as defined in the policy, you don't get the benefit.

The fine - and hopefully intelligible - print should alert you to what you're not covered for.

To the credit of Canada Life, it has produced a serious illness definitions booklet which explains in simple English what you are and are not covered for.

For example, it explains that you're covered for a heart attack (myocardial infarction), but not for angina. By cancer they mean the presence of a "malignant tumour characterised by the uncontrolled growth and spread of malignant cells and the invasion of tissue". They clearly explain that this excludes early stage skin cancers which haven't spread to neighbouring tissue. You're covered for a stroke, but only if there's evidence of permanent damage such as "paralysis of a the right or left side of the body, or disturbance of speech or vision".

Canada Life covers against blindness, but only if you've "total, permanent and irreversible loss of sight in both eyes".

Clearly, you should seek independent advice before choosing a serious illness policy. If you're not covered, arranging serious injury insurance could be the most important thing you do today.