The two deaths while the men were being taken to hospital took the total number of deaths at the crowded Sadao Immigration Centre in Songkhla province to five fatalities since January.
Volunteer doctor Anantachai Thaipratan told Phuketwan: ''I was ablle to check the condition of 80 of the people in the facility yesterday. Of those, five needed immediate hospitalisation. Two of the men died on the way to hospital.''
By the time that the men were being taken to hospital, Dr Anantachai was in the office of the Governor of Songkhla, telling him that the 302 people were being kept in impossibly crowded and unhealthy conditions.
''These people cannot move,'' the doctor said. ''They get no exercise. They are losing the use of their limbs and the consequences of continuing like this will be more deaths.''
The Rohingya men being held in Sadao Immigration are among 2000 Rohingya apprehended on boats and ''rescued'' from traffickers' camps along the border between Thailand and Malaysia in January.
Thai authorities said the Muslims, fleeing ethnic cleansing in Burma and regarded by many as legitimate refugees, would be kept in Thailand for six months while their future was determined.
With Ramadan beginning next Wednesday, when Muslims are required to not eat or drink during daylights hours, grave fears are held for the men in Sadao unless conditions improve rapidly.
In 2009, when two teenagers died among a group of Rohingya who had been held in Ranong Immigration Centre, authorities realised Ramadan would cause further deaths and transferred the survivors immediately to Bangkok, where conditions were better.
Television footage at the time showed Rohingya bent double from months of incarceration without space to move, without having being allowed sunshine or exercise.
This ''sailing season'' for the first time, children and women joined their menfolk in fleeing Burma - because their homes have been torched and displaced persons' camps are flimsy and mostly deprived of aid.
The Rohingya are being held at 24 Immigration centres and family refuges throughout Thailand, with the conditions for the women and children much better than for the men, who are virtually prisoners without any rights.
Thousands of Rohingya boatpeople have passed through Thailand on their way to Malaysia, subjected to people traffickers along the Andaman coast and reportedly sold on by renegades in the military and among local police.
Trafficking has been acknowledged by senior officers but a formal independent investigation has always been rejected.
Conditions in Phang Nga Immigration Centre, north of Phuket, were highlighted when a Channel 4 team from Britain secretly filmed the overcrowding.
Conditions there have improved, Phuketwan has been told, but the worst of the detention centres has always been reported as being Sadao.
The bodies of the two men who died yesterday are being held at Had Yai Hospital, Dr Anantachai said, and will be buried today according to Muslim custom.
Dr Anantachai said the rest of the men were being kept cramped into cells and were losing hope fast.
He said he only had time yesterday to check the condition of 80 of the men - five of whom needed immediate care - and feared more deaths.