Can you thaw out a frozen hot water heater?

the door blew off the well house and the pump gladder tank and the well it self froze up ..well have to have a new well put in which will be in next week ..but the hot water heater access door is on the out side of the trailer and it was open and do not now how long it was open and there is no heat in the trailer so am sure all the pipes are frozen in the trailer and will have to be replaced can i simply lite the water heater its a gas one and let it thaw out if its frozen or do i have to do something else to thaw it out she had no gas untill monday and thats when the well was dicovered to be frozen....there was water on saturdy and then on monday its all frozen up but there was no gas untill monday so she had no hat water so the thing was not lit