If you place a plastic cover over a cup of Hot Chocolate it stay hotter longer because the heat is trapped in a material that prevents it from escaping. For instance if you placed a tissue it wouldn't stay hot long because the tissue is made of cloth that has very tiny holes. The heat is carried by heated air which expands and so has lower density than the surrounding air and therefore rises. So if you prevent that heated air rising you prevent the loss of heat. Using a tissue, there isn't much of a pressure difference to force air through holes, though there may be a small amount of percolation. But the tissue would heat up because it is so thin, and the air in contact would be warmed and take away that heat.
<<>> another way that the lid prevents heat loss is that is prevents the liquid from evaporating. Evaporation takes a lot of heat away.
The container it's in, it insulates the hot chocolate keeping it warm for what seems like a long period of time.
a long time
The best ways to keep food warm for a long time are using insulated containers, slow cookers, chafing dishes, and hot holding cabinets.
they keep warm by sleeping in long grass.
The best way to keep food warm for a long time is to use an insulated container or a slow cooker. These can help maintain the temperature of the food for several hours without overcooking it.
its gets cold because your breathing on it and the coldness by you absorbs in to the chocolate milk.
well.... one thing that i do is drink a Hot Chocolate... and keep in my home... "home sweet(warm) home"
it can keep it warm for a very sligh amount of time
blankets, hot chocolate or tea, layers
A plastic cup will not keep hot water warm for a significant amount of time. It is not an effective insulator and heat will dissipate quickly. It is recommended to use a thermal mug or a container specifically designed to keep beverages warm for longer periods.
Wrap him/her up in a blanket to keep him/her warm or give him/her some hot chocolate.
because steel is goood