Rescue volunteers in Co Down have warned hikers to stay off mountains or risk having to save themselves if they get stranded.
After crowds of hill walkers flouted public health advice over the weekend, Mourne Mountain Rescue Team (MMRT) said they will be forced to make "difficult choices" due to coronavirus for the foreseeable future.
This includes asking the 'walking wounded' to consider rescuing themselves, and for those uninjured, lost or overtaken by darkness to spend the night on the mountains.
Those who are seriously injured, and/or unable to rescue themselves, will be attended with "the absolute minimum of team members" needed.
This means evacuations will be less straightforward and the transport to medical attention could take much longer.
Helicopter support will only be requested if a critical injury is sustained.
A statement on the MMRT page said the response team were now operating in "uncharted waters".
"While contrary to everything we believe in, these measures are necessary to protect team members, their families and our community at this time.
"Covid-19 is a very serious threat and everyone must face up to their responsibilities in order to limit its spread."
The statement also criticised those putting others at risk by ignoring rules on movement.
"By its very nature, mountain rescue requires close contact between both rescuers and casualty, exposing everyone to the risk of infection. Remember, we could also infect you!
"Our already over-burdened ambulance service and hospitals don't need or want any avoidable admissions over this difficult period."
MMRT is asking walkers, climbers, runners and bikers to stay away from the mountains and stick to confined alternatives, while strictly observing Government guidelines.
"Otherwise there may come a time when the team may not be able to respond at all. Let's all put our shoulder to the wheel now and do our bit.
"Remember, the mountains will always be there."
Many hill walkers posted messages of support for the new measures on the MMRT Facebook page.
Thomas McKenna is a member of a Community First Responder team that has been stood down over the coronavirus.
"I am also a hill walker but have not been in the hills for over two weeks. I know what it's like been confined but it's more important to beat the virus.
"Yes the Government allows exercise but there is no need for people to be going into the mountains putting your team and the over burdened health service at risk needlessly.
"When we come out the other side of this we can all enjoy the mountains again."
Last week the president of Mountaineering Ireland, Paul Kellagher, hit out at the "selfish and irresponsible" walkers ignoring the rules.
"Is your trip to the hills worth the risk of spreading the virus?" he asked.