HAVING a cold beer while turning the snags on the barbecue is an Aussie tradition but doctors are begging people to stay sober while doing it.

Sixty-six people were admitted to Concord Hospital's burns unit last year with injuries caused when gas fireballs fell out of their barbecues and onto their feet.

Half were affected by alcohol at the time and many required skin grafts and months of physiotherapy.

"Alcohol and barbecues don't mix," the hospital's burns expert, Peter Haertsch, said yesterday.

"Have a drink if you want but wait until you've done the cooking."

Burns from gas barbecues have doubled in recent years as the appliances become more affordable.

Doctors warn injuries are usually worse than those incurred from wood barbecues because liquefied petroleum gas, usually used in gas bottles, burns at 500 degrees, 200 degrees hotter than wood.

LPG is also 1.5 times heavier than air and sinks to the floor in a ball if the supply is turned on but the ignition fails to ignite the first time, causing severe burns around the feet and legs.

In July, doctors at the Children's Hospital at Westmead reported the number of children burning themselves on barbecues had risen by 40 per cent from 2006 to last year.

Among the 66 admissions at Concord - most for young men - the severity of burns ranged from 2 per cent to 65 per cent of the total body surface area, with 34 per cent of people requiring intubation and 20 per cent needing skin grafts.

Ten people suffered major complications and one person died.

Dr Haertsch said all gas bottles should be turned off fully after use and checked regularly for leaks.

He said medical authorities advised that, should a barbecue fail to light the first time, the user should wait a few minutes for the gas to disperse before trying to relight it.

kbenson@fairfax.com.au