Ecclesiastes 4:11 Halakhah

גַּ֛ם אִם־יִשְׁכְּב֥וּ שְׁנַ֖יִם וְחַ֣ם לָהֶ֑ם וּלְאֶחָ֖ד אֵ֥יךְ יֵחָֽם׃

Again, if two lie together, then they have warmth; but how can one be warm alone?

Read halakhic rulings (Jewish law) on Ecclesiastes 4:11: and classical halakhic sources.