Hot drinks are not good for us not just because they are referred to as tea and coffee but also because hot things are harmful for our body.  
 
Yerba Matte a hot drink of South America called matte and has been connected to causing cancer, yet the same herb when prepared cool and not boiled is full of healthy antioxidants. Green tea when prepared cool with the fresh leaves is also high in antioxidants. Black tea is prepaired from the same green tea leaf but it is put in the sun in piles to cure and that process causes it to mould and become full of oxidants turning it black. It is the same as taking a piece of meat and letting it spoil. The spoiling process kills antioxidants creating oxidants.  
 
As a side comment both green tea and yerba matte also have caffeine in them.