A thirsty koala suffering through scorching temperatures of 40C stopped a cyclist in her tracks and had a drink from her water bottle.

Anna Heusler and a group of cyclists were riding towards Adelaide on Friday when they spotted the parched koala sitting in the middle of the road.

They stopped to help the animal back into nearby bushland after it scurried over to Ms Heusler.

The koala was spotted in the middle of the road when it approached the group of cyclists

The koala was thirsty after the Adelaide Hills fires destroyed eucalyptus trees

'I stopped on my bike and he walked right up to me, quite quickly for a koala, and as I was giving him a drink from all our water bottles, he actually climbed up onto my bike,' she told 7News.

'None of us have ever seen anything like it.'

Ms Heusler shared the adorable yet heartbreaking images to her Instagram, showing the koala gulping water from her bottle.

'Australian Koala Bears suffering severe thirst in a heatwave. This Koala walked right up to me as I was descending and climbed up onto my bike while I gave him water,' she captioned the image.

The koala climbed onto Ms Heusler's bike and drank the water from her bottle

Ferocious fires in the Adelaide Hills have burned 25,000 hectares of land, leaving koalas scavenging for food and water.

Adelaide Koala Rescue's Jane Brister is currently caring for 46 koalas that have had their homes destroyed.

She told The Advertiser the centre doesn't normally care for this many koalas at once and the increase was due to the fires.

'A big problem we're noticing now is koalas are coming in starving… there's just no food,' Ms Brister said.

'And part of the problem is there's often at least four days until someone finds them.'

Koalas eat eucalyptus leaves - but thousands of trees have been decimated by fires.

Koalas are starving to death because bushfires plaguing the country are destroying their food and it is days before someone finds them. Pictured: Firefighter from Oakbank Balhannah CFS gives koala some water

A watch and act warning was issued for the fires burning in Cudlee Creek, north west of Adelaide, on Thursday afternoon after the blaze started six days ago - but extensive damage has been done to home and wildlife already. Pictured: Country Fire Service volunteer and koala watch blaze in Adelaide Hills

Rachel Westcott, South Australian Veterinary Emergency Management founder and rescue co-ordinator, echoed Ms Brister's sentiments.

She said the burnt wildlife are only starting to come out to look for food and water now - which is when rescuers discover their injuries.

She said many koalas have had to be euthanised due to the severe burns they have received.

Firefighters across the country are taking time to care for wildlife when they find them before handing them to the correct authorities.

Firefighters in New South Wales cared for a koala and her joey on Thursday night along Bells Line of Road.

In Victoria, where weather is reaching temperatures in the 40s, a man gave a koala a drink from a hose.