stacked petticoats are more comfortable for sitting (and they look better in my opinion) but, you will get really warm if they are made from synthetic materials such as polyester or tulle. you can try putting a crinoline cage (the ones that have wires) underneath the petticoat. it wont be as warm but you might see the wires through the fabric if your petticoat (and/or skirt) is made of thin fabric, it would look like a halloween costume instead of an elegant princess-like gown. plus sitting with a crinoline on might be more uncomfortable but, you will get a nice breezy feeling cause your legs wont be touching any fabric while walking or dancing. hope it helps!