Nothing Says I Love You Quite Like Human Experimentation

The first chemical treatment for curling hair that was suitable for use on people was invented in the year 1905 by the German hairdresser Karl Nessler (1872-1951). The first public demonstration took place on October 8, 1906, but Nessler had been working on the idea since 1896. Previously, wigs had been set with caustic chemicals to form curls, but these recipes were too harsh to use on human skin. His method, called the spiral heat method, was only useful for long hair. The hair was wrapped in a spiral around rods connected to a machine with an electric heating device. Sodium hydroxide, a strong alkali, was applied and the hair was heated (212°F; 100°C or more) for an extended period of time. The process used about twelve, two-pound brass rollers and took six hours to complete. These hot rollers were kept from touching the scalp by a complex system of countering weights which were suspended from an overhead chandelier and mounted on a stand. His first experiments were conducted on his wife, Katharina Laible. The first two attempts resulted in completely burning her hair off and some scalp burns, but the method was perfected and his electric permanent wave machine was patented in London in 1909. It subsequently went into widespread use.
-http://en.wikipedia.org/wiki/Permanent_wave

His wife must have been a rather brave or timid person. Either would have sufficed.