The Ampilatwatja community, northeast of Alice Springs, is without mobile connection after Telstra shut down its 3G network on Saturday and temporarily turned off 4G connectivity until this Friday to carry out upgrades.
The Ampilatwatja Health Centre Aboriginal Corporation, which delivers primary health care, including ambulance services, in the community, is relying on its satellite service.
But it has lost all communication with outstation health services, chief executive Darryl Coulstock said on Wednesday.
There was a serious incident on Saturday involving an unconscious woman who had to be airlifted for treatment and it was "just lucky" that someone had a car and drove to a nurse's house, he said.
The woman was airlifted for treatment by the emergency retrieval service.
Mr Culstrock claimed Telstra's Indigenous liaison representative in Darwin told him they should have rung 000.
"If the whole network is down, how do they do that?" he said.
"I told him if someone dies because they haven't been able to call us, I will personally go to the coroner and explain the situation, that I've tried to get this sorted.
"Telstra have not taken the community safety into consideration at all in their decision-making."
Mr Coulstock said there was no prior warning of the 4G outage and he made contact with the Indigenous liaison representative when the service was still out on Monday.
"And his response was, 'well, it's going to be a minor convenience, but there's nothing we can do about it'," he said.
"I said, 'It's not a minor convenience. You're actually putting lives at risk because we are four-and-a-half hours drive on a bad road from Alice Springs'."
In a statement, Telstra Regional General Manager Nic Danks said the site upgrade in Ampilatwatja had been requested by the community and local government for over five years and had to be completed before the upcoming wet season.
"There is only one base station in the community which needs to be turned off to perform the works to upgrade the tower," he said.
"Whenever we do works of this kind, we do all we can to minimise the time offline and make sure we advise local stakeholders, including government and emergency services, which we did on October 29."
Telstra said it also sent text messages to residents advising of the works.
Mr Coulstock wants Telstra to have a plan in place to ensure some level of mobile connectivity remains as upgrades continue throughout the Barkly region, and other remote areas.
"It just infuriates me, such a lack of understanding of the risks with what they're doing," he added.