You can't perform any medical procedure on anyone unless they consent so the first step in any first aid protocol is always something like, "I know first aid, can I help you?" However, an unconscious/unresponsive person is always assumed to consent to a life saving intervention.
For example, if you have a choking victim, who can't breath, and you ask if you can help and they shake their head and wave you off, you have to stand back and wait. Once they pass out and are unconscious, then you can intervene, because an unconscious person is assumed to consent, even though just a few moments earlier they were a non-consenting conscious person.