I am using "Temperature Monitor" v4.11. smcFanControl shows the same temp. Its "CPU A temperature monitor".
To get it to 107 Celsius, I had 4 "yes > /dev/null" running, then running Cinebench OpenGL benchmark repeatedly. The temp gets up that high while the machine is still overall cool and the fans are slowly spinning up. Once the fans are really cranking the temp maxes out around 97.