It's an acronym for first aid steps, taught worldwide.
But the first step - D - doesn't involve touching an injured or unwell person, or even checking their responsiveness.
It stands for danger.
And everyone - from school children building their CV to paid paramedics - is taught to check for dangers first, before proceeding to help.
If you can't protect yourself from the life-threatening hazards then you don't get any closer, because if you get hurt, you can't apply first aid and there's one extra person needing help.
When Whakaari / White Island erupted at 2.11pm on December 9 last year, our New Zealand rescue helicopter managers initially ruled the volcano too volatile, too unsafe, for pilots and paramedics to land.
By about 4pm they had more information about the eruption and how to best protect staff from harm, and two rescue helicopters were sent to the crater.
But when crews landed and assessed the remaining victims, none were alive.
Under the DRSABCD approach, our rescue helicopter services did the right thing.
But they've been hounded since the eruption because they did not fly to the island and land immediately.
The criticism continued in an Australian 60 Minutes segment that aired in New Zealand last night and is currently available on Youtube.
Private helicopter pilots, who had been taking tourists to the island for years, were praised for landing on the island and flying out the last survivors who could not immediately evacuate on boats.
60 Minutes' narration described it as a "devastating blow" for the pilots and victims, finding out rescue helicopters weren't landing alongside them, amid the extreme dangers.
Survivors believed their recoveries would have been faster, and loved ones' lives could have been saved, had rescue helicopters not held back.
NZ Police was the lead agency that coordinated the search and rescue and St John medical director Dr Tony Smith was on one of the rescue helicopters that eventually landed on the island.
He told 60 Minutes that, looking back with what he and his colleagues know now, paramedics could have landed on Whakaari earlier but they made the best decisions they could with the information they had at the time.
Smith told NZME in June that since the eruption, he had heard from peers who thought rescue helicopters should have gone earlier.
Others told him crews went at the right time and others still said they shouldn't have gone at all.
Crews had plenty of reasons not to go.
The force of the eruption shunted a tourist helicopter off the landing pad, leaving it crumpled and unable to fly.
There was a serious threat of losing rescue helicopters and crews to a similar, subsequent explosion on the crater.
Eruptive episodes can last for months, sometimes years, with GNS assessing the likelihood of another eruption as high as 60 per cent in the days after the crater blew.
There were also many other urgent tasks rescue helicopters and paramedics were desperately needed for, to save the lives of eruption victims, in safer conditions on the mainland.
In total, 11 rescue helicopters from as far south as Nelson, were part of the response.
This included treating and triaging patients for hours at a makeshift triage centre set up at Whakatāne, and transferring victims to specialist burns and intensive care units as quickly as possible.
The crews worked through the evening of December 9 and overnight to fly the injured out of the Bay of Plenty to specialist burns and intensive care units, from Auckland to Christchurch.
Subsequent transfers also took place in the days and weeks after the eruption.
Who would have performed those tasks if we'd lost rescue choppers and key expertise in an eruption on the island?
These rescue helicopter services aren't fully government-funded, nor is St John, but they pull together what they can with the help of donations, to get the best aircraft, medical apparatus and people to save as many people in perilous situations as they can.
Even with a cautious approach, harm to our rescue helicopter services and paramedics still happens.
Perhaps the best reminder of this is the Auckland Islands rescue helicopter crash in April last year.
A pilot, winchman and paramedic were on their way to the subantarctic Auckland Islands when their aircraft crashed into the sea in April 2019.
Despite head knocks and fractures and the extreme cold, they swam 20 minutes to Enderby Island and survived.
Can we blame our rescue helicopter directors for protecting their staff from another crash around an isolated island, in an extremely hazardous environment, just eight months after the Auckland Islands crash?
We can only imagine what the victims went through on December 9, nor can we fathom how hard it was for our emergency services.
Our rescue helicopter services took a conservative and controversial approach to the situation but they followed the DRSABCD golden rules.
They saved lives, treating and transporting victims on flights across the country, and protecting their own.
Let's not forget that.