Friction paradox: why does relative motion affect heat dissipation?

[VVS2000]

I was reading this book on mechanics by derek raine and came up on something called friction paraddox.
Suppose a block is is moving with constant speed and the external force is balanced by friction. We know friction causes heat dissipation and the external force supplies some energy so as to keep the speed constant.suppose I run along with the block at same speed and with respect to me, block is in rest and there is no heat dissipation. So how come I have beem able to remove the need for supplying energy just by changing my frame of reference? Thanks in advance!

 

[phinds]

So how come I have beem able to remove the need for supplying energy just by changing my frame of reference?

You haven't. In your frame of reference you are expending energy to move the floor under you.