Charles Ellicott Commentary Ecclesiastes 4:11

"Again, if two lie together, then they have warmth; but how can one be warm [alone]?" — Ecclesiastes 4:11 (ASV)

They have heat.— The nights in Palestine were often very cold, and it would seem (Exodus 22:26) that it was common to sleep without any cover but the ordinary day garment; though see Isaiah 28:20.