The blaze engulfed the poor family's home, made of wooden planks and covered by bushes in Gorakh Hills area of Dadu district.
A police official said that that the poor family was living in hut and was using fire to keep them warm in freezing night of December, when temperature drops down to near zero degree centigrade.
The fire got out of control and burnt the hut, Hakim Ali told PTI.
The village is located in what is usually the coldest area in winter. Most household in poor countryside areas use fire to keep themselves warm in the winter nights.
Fires are common during cold weather in Pakistan, where a large segment of the population lives below the poverty line in huts and homes without proper heating.