Loose belt -- replace or lubricate
ADD-ON If it is a metallic squeal that continues for a minute or so after the car starts it could be your water pump bearing. Get your mechanic to check it out and replace before you need a tow truck.
The squeal when you turn on the AC or heater is a loose fan belt. It may be cracked and need replaced, or it may just need tightened.
Usually when a car makes squealing sound after accelerating with the heater on, the serpentine belt is a little loose. It likely needs adjusting by a professional.
Its happening to me too i'm almost convinced its a loose serpentine belt
power steering
It depends on your car, but should be very obvious.
Alternator is not making enough power.
To go out about 5min. early and turn the car on and heater so that the car can be warm when you leave.
there seems to be a short in the electrical system, i would start by checking the heater switch,
No heat when you turn it on in the car.
your car gets warm............ or hot........
the right because it is getting the full weight of centrifugal force on it it will tend to slip hence the squeal
At least inspect when you hear squeal. Base further work on what you see.