A glass container would keep liquids hotter as it retains heat better than plastic Glass is less likely to conduct or disperses heat than plastic.
Does A Plactic Or Glass Container Keep Liquids Hot Longer?
It depends on how the container is designed.how thick or thin is it .is it double walled or honeycomb design. Or insulated. Or is it a plastic container inside a metal container...or is the glass and plastic treated in any way. Dyed,colored,tinted....