In case you missed this:
The problem of hot cabins and the sensation of coldness has been discussed at length in the past. Any temperature over 78 degrees and the DRY air decreases the exchange of Blood levels of Oxygen & Carbon Dioxide in the lowered pressure cabins resulting in shortness of breath, headache, anxious feelings, etc.
Of course, they should use the blankets, sweatshirts, sweaters, if they
feel cold! But the cabin temperature should not be raised for everyone to compromise their health! It appears that eludes your understanding.
Seems like we were talking about 2 different things. I was referring to cabin temperature on JAL flights while you kept talking about 78F. Although I don't travel with a thermometer, I have never experienced anything close to 78F up in the air on JAL metal.
I've spent ~800 hours on JAL flights in the past 10 years, the only time I experienced something close to 78F inside a JAL plane was when it was parked at NRT waiting for departure. But that's the summer after the Tohoku earthquake and I don't mind as it had to conserve energy for the area.