We didn’t have a hot water shower. So it was a little complicated to take a shower in the winter. By the way, we didn’t have heater either.
The essential device was a big plastic bag shaped like a cone, about 6 feet tall. My mom hangs the bag up using a clothes hanger. She brings in a big thermos bottle filled with hot water and a big plastic container of cold water. We place a big wood bowl inside of the plastic cone and pour some hot water into the bowl. We then use shoes to weigh down the corners of the plastic bag to create a sealed room. I will wait for the steam to fill the bag then strip as quickly as I can and get in the cone.
The same plastic bag lasted all my childhood and my teenage days. Surprisingly good quality. The metal ring to hold the wood bowl together was re-tightened about 5 times.
I am writing this down now. If someday, I get a bedroom-sized bathroom with 2+ heat vents, heated natural stone floor plus heated towel racks, I would laugh at myself so hard.