North Yorkshire's emergency services have gone into "full emergency mode" due to a rise in coronavirus cases and nationwide issues with testing capacity.
As part of the move, local testing facilities have been redirected to work with the areas in greatest need, care homes are receiving extra support, and the reopening of social care day services has been paused.
The number of cases in the country have more than quadrupled in the past two weeks.
It comes as Health Secretary Matt Hancock announced new lockdown measures for areas of the northeast - but not North Yorkshire.
The North Yorkshire Local Resilience Forum (NYLRF) - which includes the emergency services, local authorities and the NHS - has said Selby, Harrogate and parts of Scarborough and Craven have rising numbers of cases.
The NYLRF added that there is growing evidence of community transmissions in Whitby, Sherburn-in-Elmet and the Crosshills area.
Richard Flinton, the chief executive of North Yorkshire County Council, said: "Together, over the last six months, all of us who live and work in North Yorkshire have made a huge effort to prevent and reduce the spread of COVID-19 locally.
"We thank everybody again for their many sacrifices. However, as we have seen nationally and around the world, cases are rising again and the threat of the virus is a real and present danger."
Dr Lincoln Sargeant, Director of Public Health for North Yorkshire, said: "There are significant limitations with laboratory capacity nationally, as demand for tests increases.
"We know that Government is working to address this situation but, in the meantime, it means that fewer test appointments are available and test results are taking longer to be processed.
"This issue is a national one and outside of our control. We have escalated our concerns nationally and we are targeting our local testing facilities towards the communities and people in greatest need".
Mr Flinton added: "We know how quickly infection rates can change and we are calling on the whole county to act now with us in response.
"Please show extra restraint and caution and to take additional actions above and beyond those required nationally to help us try to avoid another lockdown here."