Freezing temperatures will probably hamper the efforts in the eastern Quebec town of L'Isle-Verte.
Five people are confirmed dead, while another 30 are reported missing.
The cause of Thursday morning's blaze is unclear.
Most of the residents probably never had a chance — many of them were over 85, had little or no mobility and were confined to wheelchairs or walkers.
A common theme in conversations in the town of 1,500 was the parallel between the fire and the train derailment which devastated Lac-Megantic last summer.
Both tragedies occurred shortly after midnight and left the two communities reeling.
