A DEPARTMENT of Health health alert issued for the south-west tomorrow has been extended to include Sunday.

Councils around the region have enacted their heatwave plans as temperatures are expected to soar to the high 30s and low 40s in towns including Mortlake, Hamilton, Casterton and Camperdown.

Areas along the coast are expected to beat the heat tomorrow, with Warrnambool forecast to reach a top of 29 while Port Fairy is only expected to reach 25. The mercury will climb in Warrnambool on Sunday, with a forecast top of 34.

Corangamite Shire's health alert said high temperatures had the potential to cause heat stress and cause significant health impacts and reminded residents to exercise extreme care during the heatwave.

The council asked residents to take precautions including drinking plenty of water, staying indoors, wearing light weight, loose-fitting clothing and to reduce physical activity.

The alert also reminded residents to check on older, sick and frail people who might need help coping with the heat and says if you must bee out in the heat to limit outdoor activity to morning or evening hours.

A low pressure system is expected to sweep across Victoria on Monday, bringing a milder southerly airstream that will see maximum temperatures between 25 and 33 degrees on Monday and Tuesday.

jwoolley@fairfaxmedia.com.au