^{Editor's note: I'm maintaining here information from user Roger until he decides to migrate on his own.}

Answer to the question: "Can you add a link or citation that confirms that the temperature of Steve's ions was actually measured by the TII?"

Have a look at the presentation from Eric Donovan at the 4th Swarm science meeting in Banff: http://www.esa.int/spaceinvideos/Videos/2017/03/Opening_of_Swarm_and_CryoSat_Science_Meetings around the time 1:22:14 -> after almost 25 seconds the actual Swarm data are shown (from top to bottom: ion velocity, magnetic anomaly, ion temperature and electron density).

Answer to the question "how did the ESA probe measure Steve's temperature?": The ion temperature is measured by an Thermal Ion Imager (see http://efi.phys.ucalgary.ca/)