It’s less than 20 degree hotter than human body temperature, which implies that it would not actually cause you to jerk your hand back.
Others describe it as the temperature a baby’s stomach will scald. Have you boiled water to 110 degrees (tested it with a food thermometer) and actually put your hand in?
First it is the shita of R’ Moshe Feinstein TZATZAL that we have to be machmir that 43 degrees Celsius (approx 110 degrees F) as stated in (IGROS MOSHE ORACH CHAYIM (4:74) UNDER bISHUL NOTE GIMMEL) “HU KVAR CHOM GADOL SHEYESH LACHUSH LYAD SOLEDES KEFI MAH SHEHBDAKNU BATZMEINU. VEHASAFEIK YESH LACHUSH AHD 71 MAALOS CELSIUS (APPROX 160 DEGREES F) HU VADAI YAD SOLEDES.”
http://hebrewbooks.org/pdfpager.aspx?req=920&st=&pgnum=137
I am pretty sure that R’ Shlomo Zalman held it was 45 degrees Celsius (113 degrees F).