Sydney residents prepare as temperatures set to soar into dangerous territory

Sydney has started a stretch of searing heat, with temperatures expected to exceed 40C in the west tomorrow.

Fire crews are on high alert with a total fire ban in place for most parts of the state.

Firefighters in the Blue Mountains sprang into action today, with the bush extremely dry and a fallen tree branch which hit power lines posing a dangerous fire hazard.

Elsewhere, residents were preparing for tomorrow's severe fire danger warning as volunteer firefighters got ready for a busy few days.

Total fire bans will be in place across the Sydney area, due to the extreme conditions.

Temperatures throughout the west will be above 40C, with a top of 43C in Penrith expected.

If it exceeds that, it will be the hottest November day since 1997.

Warm north-westerly winds of around 25 km/h will also add to the bushfire danger.

The young and elderly are considered most at risk during the extreme heat.

Late this afternoon, a shark sighting forced a mass evacuation at a packed Bondi Beach - but with tomorrow's heat, the huge crowds are expected to be back.