The house temperature is about 21c and is comfortable enough for a Sukiyaki meal. We bought the veggies and beef from a supermarket and using our portable gas stove, we started cooking the Sukiyaki. The soup was prepared by my wife and overall the meal was satisfying and yummy.
The reason we own a portable gas stove is because Japan is quite prone to have power line cut off during earthquakes or typhoon. Under such circumstances, even without electricity we can still cook our meals. We also keep a number of important items that are needed for survival eg: bottles of water, dried food, canned food, torchlights, first aid kit etc.