Your blood. :)
no. it keeps your body cool.
protects the body and keeps it warm
feather
keeps you warm (fat)
No because their body fat keeps them warm.
Because it traps the heat that comes from your body from escaping, so you have more heat so it keeps you warm.
your skin is not what keeps you warm its your body temperature
keeps us warm by maintaining body temperature.
It depends, in general I would say body heat.
Sweat glands do not keep us warm. They secrete moisture through our skin which evaporates into the air cooling our skin and blood but moisture that does not evaporate and remains as liquid on the skin is not efficient in cooling.
Seals have blubber, a layer of fat, which keeps them warm.
A blanket keeps you warm by trapping and retaining your body heat, creating a layer of insulation that helps to maintain your body temperature.