MRE's: Military grade pouches of food that will get you through. Make sure to pick up the ones that do not freeze. They taste like ass, but you won't die of starvation.
Poland: Conquered by Austria, Prussia, Russia, Partition Period (Poland stopped existing) France, Germany, USSR
Gas Mask: Poisonous gases are a major cause of death in mining disasters. This is a must to keep you breathing and also protect the eyes from dust and debris.