In his first sleepout, he has raised a whopping $64,704, well on his way to achieving his fundraising target of $65,000.

As of Wednesday, Mr Hood was also third in Australia for fundraising, behind Bank SA chief executive Nick Reade (nearly $138,000) and Perth-based Crown Resorts CEO Barry Felstead, who had raised nearly $105,000.

Next in line for the Canberra CEOs, is the Australian War Memorial's director Brendan Nelson, with $18,160, also close to his $19,000 target.

Canberra-based Scouts Australia chief commissioner Neville Tomkins is also this far from achieving his target of $18,000.

Mr Hood, who has also worked at Air Services Australia and Civil Aviation Safety Authority, said he worked his contacts in the aviation industry.

"And that's ranged from Dick Smith to heads of airports to heads of airlines," he said.

"But even more important are those who can't afford to give but still do. I feel quite humbled and quite privileged that people have chosen to sponsor me."

(He also hit up Nationals Senator Fiona Nash after they sat side-by-side in Senate estimates.)

Mr Hood also praised his staff who had pledged money to help St Vincent de Paul help the homeless in Canberra.

"It strikes me, having lived in a number of different locations in Australia and, in fact, the world, here in the heart of the nation's capital, the number of homeless seems to be quite extraordinary," he said.

"Even here at the ATSB building, in a little alleyway, there is someone sleeping there most nights.

"I think the plight is probably worse than most people realise."

Vinnies says more than 1700 Canberrans face homelessness each day, including an estimated 289 children

We have to congratulate all 99 CEOS taking part in the sleepout in Canberra, which is just about the toughest gig and definitely the coldest night of any city participating in the sleepout.

These bosses will be sleeping rough outside Old Parliament House on Thursday night with the overnight temperature expected to dip to minus three degrees.

(That's far and away the coldest night ahead for bosses around Australia. Heck, the CEOs in Melbourne will have a positively balmy low of seven degrees.)

Vinnies has helpfully given the CEOs some tips for keeping warm including padding their coats and pants with newspaper for extra insulation. They will also have a sleeping bag and three pieces of cardboard.

More than $3.8 million had been pledged nationwide by Wednesday, with the ACT contributing nearly $309,000 to the appeal.

Others participating in the Canberra sleepout include Canberra Toyota dealer principal Mirko Milic, Clonakilla chief winemaker Tim Kirk and ACT Policing chief police officer Justine Saunders.

In Canberra and Goulburn, Vinnies provided 82,153 bed nights in a year. The Vinnies Blue Door service provides 170 nutritious meals each day. And there were nearly 13,000 instances of support from the Night Patrol last year.

If you'd like to donate to any of the CEOs go to www.ceosleepout.org.au