People are putting lives in danger by calling 999 when they have a temperature or cough, the Northern Ireland Ambulance Service (NIAS) has warned.
The NIAS is asking members of the public to only dial 999 in emergency situations.
Ambulance service crews have no ability to test for Covid-19, so calling them out is putting their lives at risk.
The NIAS urged the public to thick twice before dialling 999.
A spokesman said: "We are asking members of the public to assist us in our ability to respond to the Covid-19 crisis by only calling 999 in real emergency situations.
"We would like to thank the public for their co-operation in how they have responded to this request.
"However, there continues to be an increasing number of calls in which ambulance crews report that they arrive to find that the true nature of the call is early symptoms of coronavirus.
"(These people have) either a temperature and/or a new and continuous cough and what is being sought mostly is reassurance about whether or not the patient has coronavirus.
"NIAS crews cannot carry out a test to determine this."
The service said that instead of calling 999, members of the public should follow Public Health Agency (PHA) guidelines.
"The PHA advice is clear. If you or anyone in a household has a high temperature or a new continuous cough, everyone in your house must stay at home and follow advice on how to isolate at home," the spokesman said.
"You can ring NHS 111 for information and advice and they can help decide if you need to contact your GP. To avoid spread of the infection, patients are asked not to go to their GP surgery or pharmacy.
"The public, quite rightly, have been effusive in their praise for our staff and other healthcare workers who are at the forefront in battling this virus.
"We would urge the public to help these staff by not calling unless it is a genuine emergency."