Washing machines and dishwashers "add to heat in the home" and are wasting water if they are not full, suggests Dubbo Regional Council's chief executive officer (CEO) Michael McMahon.
The CEO is offering Dubbo residents advice on water-wise practices and their personal safety in heatwave conditions.
The Bureau of Meteorology is forecasting top temperatures of 41 degrees Celsius on Thursday, 43 degrees on Friday, 45 degrees on Saturday and 42 degrees on Sunday.
The extreme temperatures may make it harder for residents to adhere to level four water restrictions with a usage target of 280 litres (L) per person per day.
In the week ending last Sunday, residents used 348L per person per day.
But Mr McMahon is urging them to continue to observe water restrictions in the heatwave while taking care of their health and well-being and looking out for neighbours.
"This week more than ever we must all keep an eye out for fellow workers, family and friends and particularly the young and the elderly," he said.
Mr McMahon said NSW Health recommended cold drinks and smaller cold meals such as salads and fruit on hot days.
He also suggested wearing light-coloured, loose-fitting clothes made from natural fibres like cotton, staying out of the sun where possible and avoiding the outdoors between 11am and 5pm
The CEO is asking residents not to water outdoors before sunset on Wednesday and Sunday and limit use of washing machines and dishwashers.
"They add to heat in the home and unless there is a full load, save water and wait until washing machines and dishwashers are full," he said.
For information on saving water visit www.dubbo.nsw.gov.au/droughthub.