Plane HVAC is always terrible

One thing a plane is consistent on is being a horrible temperature. It does not matter if there is heating or cooling, the plane ride will be awful. I have been on airplanes that have the heating system cranked because it is Winter. It is horrible sweating in that sticky seat and being jammed right next to a stranger. You can feel the heat waft off of them and see their sweat stick to the seat. The little cooling vent doesn’t seem to do anything either. When the plane decides it is in heating mode, the AC vent only will push out hot air. You can’t adjust the amount of heating either. In the Summer, the AC might even be worse. I hate going outside in the hot weather and getting too warm. But, being icy cold on a plane right after is horrible. We dress for the outside. So why would the plane’s temperature be so vastly different? In the Winter, there should be hardly any heating since everyone is bundled up anyway. In the Summer, the airline should lay off the cooling. I always wear shorts and a tank. I am not willing to bring a jacket because the plane loves to blast theri air conditioner. But, I usually end up suffering through a 2 hour plane ride shivering to death. It is horrible, but apparently the airline has to do it. I wonder if anyone is comfortable with the heating and air that the plane gives us. I know I would rather not have any than what they give us.