My brand new KA Pro 600 got very warm today mixing 4 loaves! It really worried me. I will likely go to 3 loaves or 2 batches of 2 loaves in future as someone above mentioned doing. I have hand mixed 4 loaves and regretted it…had to take Ibuprofen and lay down on my yoga mat! ( : But two loaves was fine for me hand mixing. Maybe I’ll just do 2 in KA and 2 by hand.