CARACAS, Venezuela — Food shortages were already common in Venezuela, so Tabata Soler knew painfully well how to navigate the country’s black market stalls to get basics like eggs and sugar.

But then came a shortage she couldn’t fix: Suddenly, there was no propane gas for sale to do the cooking.

And so for several nights this summer, Ms. Soler prepared dinner above a makeshift fire of broken wooden crates set ablaze with kerosene to feed her extended family of 12.

“There was no other option,” said Ms. Soler, a 37-year-old nurse, while scouting again for gas for her stove. “We went back to the past where we cooked soup with firewood.”

Five months of political turmoil in Venezuela have brought waves of protesters into the streets, left more than 120 people dead and a set off a wide crackdown against dissent by the government, which many nations now consider a dictatorship.