Canberra grandfather injured after collapsing during morning walk

The 77-year-old grandfather had left home at 7.15am, a little earlier than usual so he would be back in time for the opening of presents with his family.

It had been a relatively warm start to the day and temperatures would climb to 19.7 degrees by 9am.

"I felt fine, I felt no different from any other day," he said.

Mr Milne, a former diplomat, did not remember much about his walk and his next memory was waking up in an ambulance.

He had collapsed about 10 minutes into the walk and fortunately passing motorist Geoff Campbell saw him lying on the pavement.

"He apparently drove past and saw me prostrate on the footpath, turned around and picked me up," Mr Milne said.

Although he does not remember anything, Mr Milne was able to tell Mr Campbell where he lived.

After being taken home, Mr Milne was rushed by ambulance to the emergency department, where doctors discovered he had fractured bones and nerves in his cheek.

Mr Milne spent six hours in the emergency department, with doctors telling him he had collapsed from dehydration.

"I've not fainted before or collapsed. It was so out of character and I realised that what I'd done was not drink enough water," he said.

"It was warm (in the morning) but I suspect it was because I hadn't drunk enough water in the preceding 24 hours. It was a lack of consciousness on my part of the dangers of not drinking enough."

Mr Milne – who is still bruised and experiencing numbness on the left side of his jaw and face – is expected to make a full recovery although he was told his facial injuries would take three to four weeks to heal.

"I can't speak highly enough of the emergency department here and the ambulance staff. As far as I'm concerned they were super and they were very thorough," he said.

Mr Milne's story comes after a warning from doctors in Canberra about the dangers of heat-related illnesses after a rise of emergency department visits due to the heat earlier this month.

"I couldn't urge people more to be very conscious of the impact that the heat has on one's wellbeing," Mr Milne said.

"It (my collapse) was a wake-up call and it's certainly left a mark with me and I'm drinking eight glasses of water a day."

Mr Milne said he was deeply grateful to Mr Campbell who stopped to help him.

"I consider him a good samaritan," he said.

"It was a wonderful act on his part that he should respond like that. Who knows what might have happened next (if he hadn't stopped)."

Mr Campbell, also from Chapman, doesn't think his actions were heroic and said he was simply doing the right thing.

"I thought I'd better stop in case there was something wrong," he said.

"I'd hope somebody would do it for me or my family if it happened. It's just something I think we should always do."