The second lecture in Burgas's first aid training series covered cardiac arrest and how to use a defibrillator. It was given by Dr Svetoslav Todorov, deputy director of the University Hospital in Burgas.
Dr Todorov showed where to check the pulse of an adult and of a child. He also explained why the saying "I swallowed my tongue" is wrong.
He said the first reaction is vital, and the more people who know how to act correctly, the better.
"If we find a person with no pulse, we must call 112 at once and, before that, start life-saving chest compressions," Dr Todorov told Bulgarian National Radio. He added that compressions on a child are done differently from those on an adult.
The doctor said using a defibrillator is especially important. He advised people to follow the device's instructions and not to be afraid of it. A defibrillator can be used on anyone who is unconscious.
"There is nothing scary about it. If it is not attached properly, it simply will not work," Dr Todorov said.
Burgas already has defibrillators in several places in the city. Police cars are due to get them from next year.
More first aid training will be held next year.