joules has it right! My DP and I attended a free first aid course because our village has been running a campaign for 3 defibrillators, which are used for basic life saving incidents eg heart attacks.
We could not believe how much we learned in 4 hours. Also it was amazing how research into first aid has developed due to real-world incidents, with knowledge gained feeding back into first aid courses.
For example, the use of rescue breathes is considered far less effective than chest compressions, in fact they said dont waste precious time giving mouth to mouth, far better to use your energy on the chest, that has greater chance of saving someones life.
I wont profess to remembering everything from the course, but it was a great experience.
rissoles I can recommend you and DH do a first aid course together, it will really be an eye opener for your DH far better than Doctor Google. Our trainer had been in the Road Traffic Accident unit until he retired, so he gave lots of real world examples and helpful advice esp. If you have children who swallow something by accident ( theheimlich manoeuvre and all that jazz)
I have become quite evangelistic about it, as it would be amazing to contribute towards saving a life!