A firefighter battles flames in Kersbrook in the Adelaide Hills, where the worst fires are burning

Hundreds of firefighters are facing extreme conditions as they attempt to contain a fire burning out of control on Adelaide's north-eastern fringe.
The bushfire, now burning into its sixth day, has already destroyed or badly damaged 38 homes, and burnt more than 12,500 hectares.

 A firefighter battles flames in Kersbrook in the Adelaide Hills, where the worst fires are burning. Photo / News Corp

The Country Fire Service has become more confident in recent days it will be able to contain the blaze, and was boosted on Tuesday by forecasts of easing conditions later in the evening with the possibility of some rain.
But more than 500 firefighters, including reinforcements from interstate, will first face extreme heat with the temperature to soar to 38C for a second day in a row, and winds expected to shift from north-west to north-east, presenting dangerous conditions.
CFS state co-ordinator Brenton Eden warned it was likely there would be "significant flare-ups" within the perimeter of fire. He said, however, the areas of concern were heavily resourced.

The CFS said the Sampson Flat fire was continuing to burn and cause concern in a number of areas, including near Kersbrook where 12 homes have already been lost.
"There are numerous areas of unburnt ground within the perimeter of the fire," the CFS said, which still has a "watch and act" alert in place.
The Bureau of Meteorology said increased humidity and the chance of rain could work in the favour of firefighters.
A very strong intrusion of tropical air from the Pilbara in Western Australia, combined with a Southern Ocean disturbance, could provide up to 200mm of rain in the northwest of the state and smaller falls near the capital over Thursday, Friday and into the weekend.