This is the expert view of the terrorist's state of mind and body, 11 days into his escape from the Whitley Road Detention Centre on Feb 27. Being constantly on the run is an energy-sapping ordeal, said Mr Ivan Pung, 31, who works as an adventure leader for local adventure company X-trekkers.

He was also a commando in the army for four years and had gone through one- and two-week jungle survival courses.

Former commandos like him told The Sunday Times that finding food and water is key to jungle survival. Without these basic resources, the body will swiftly weaken and the person may even become delirious.

Mr Pung recalled that as a commando, when he went for four days with only small meals of fruits and vegetables in the forests of Brunei, he would tire easily and feel sleepy.

'That is the body going into hibernation because it wants to conserve as much energy as possible,' he said.

It is fine if the person can set up a base somewhere near a water source and subsist for a few days. But if he needs to be constantly on the move to avoid detection, it becomes exhausting.

Asked if the wet weather in the last few days would have helped him, Mr Pung said that it was both a blessing and a curse.

On the one hand, it will help Mas Selamat cover his tracks and increase his water sources. On the other hand, being constantly wet in the forest may cause him to fall sick more easily.

Mr Pung said that if the fugitive is indeed in the forests, it won't be long before he gets smoked out.

'The military here knows our forests inside-out and the jungles are not big and dense like those in Malaysia and Indonesia,' he said.

Criminology experts overseas who have commented on fugitive cases elsewhere say that fugitives are dangerous, desperate and would not hesitate to hurt others to get what they want.

Like Mas Selamat, they have to make a choice: between holing up somewhere like a jungle and feeling like a sitting duck, or going on the run but risking being exposed.

Psychologically, however, consultant psychiatrist Adrian Wang feels that Mas Selamat will be a tougher nut to crack.

As a hardened criminal used to living in solitude under confinement, he would be comfortable being alone and will not crave human interaction like regular people would, said Dr Wang yesterday.

'People like us will be crying to come out of the jungle within a few days. But Mas Selamat looks like he may be capable of enduring hardship for weeks or months,' he said.

He thinks that, ultimately, it will be the fugitive's physical needs that prove more urgent than his mental ones.

But people like him - who are galvanised by strong convictions and beliefs - do show 'an unwavering kind of strength'.

'I think that everyone has a breaking point,' said Dr Wang. 'We just don't know what his breaking point is.'

chengwee@sph.com.sg