The ban – rated very high, which started at midnight, covers the following councils: Cessnock, Dungog, Lake Macquarie, Maitland, Muswellbrook, Newcastle, Port Stephens, Singleton, Upper Hunter

Paramedics also issued a warning to keep cool, with some parts of the region due to hit 37 degrees before the weekend. 

While the sweltering spike is expected to drop away, as showers develop on Saturday and Sunday, it will offer little change in Muswellbrook and Singleton, where temperatures have been forecast to sit in the mid-to-high 30s until Tuesday.

The NSW Rural Fire Service (NSW RFS) provides the following advice:

Under severe and very high fire conditions:

* Well prepared homes that are actively defended can provide safety during a fire;

* Follow your Bush Fire Survival Plan and remain vigilant;

* Keep informed by listening to local radio, watching television news broadcasts and monitoring www.rfs.nsw.gov.au

The NSW RFS may issue a Harvest Safety Alert for areas of heightened risk. 

Harvest operators should monitor conditions and regularly check that they are operating within guidelines.

No fires may be lit in the open and all fire permits are suspended during a Total Fire Ban. 

Gas and electric barbeques may be used provided certain conditions are met. 

Total Fire Ban rules and a map of current Total Fire Ban areas are listed at www.rfs.nsw.gov.au