Hands only CPR is definitely better than doing no CPR at all. However, traditional CPR (which involves chest compressions and rescue breaths) is still recommended as the best option in most cases. An automated external defibrillator (AED) is also an important device to have available as it can help to shock the heart back into normal rhythm if it has stopped completely. The type of CPR used will depend on the specific situation and the training of the person providing first aid.
