[Joseph F. Smith, John R. Winder & Anthon H. Lund]
It is not in order for people to ask for recommends for second blessings. They should be chosen through the Stake Presidency because of their faithfulness, fitness and worthiness to receive this higher ordinance of the house of the Lord. It is understood of course that you have received second anointings yourself, otherwise you had better refrain from recommending for the present. We may say however that second blessings are not administered to single individuals of either sex, but to men and their wives.
[Source: Joseph F. Smith, John R. Winder, and Anthon H. Lund to Thomas E. Bassett, Jan. 5, 1902, in Anderson, Devery; The Development of LDS Temple Worship, 1846-2000: A Documentary History, http://amzn.to/TempleWorship]