How was charcoal used during the middle ages?

Charcoal was and is still used for many things, from getting warm to punishing the robbers, they used charcoal in fire, they used charcoal for the brass burning punishment, and many more!

Brass burning punishment:

when coal is put underneath a brass case, the victim is put inside naked and they get really burnt! depending on the crime, the longer they stay in there!

I hope this helped!