What temperature are Pitot Tubes heated to?
This page talks about the Pitot probes that operate at temperature range -65°C to +70°C. They are FAA TSO-C16 and Military Approved. It is probably unwise to heat them more during normal operation. This is not very hot but +70°C would already burn the skin. The probes are used at Pilatus PC-12, Bell 212, Bell UH-1 Special, Cessna Caravan, Diamond DA42, IAI Heron and Quest Kodiak.

This contradicts another source where heater temperatures of 200 °C are reported, and also this industrial Pitot device (while not used on the aircraft) is rated up till the 200 °C, so the design itself allows the temperatures that high. However the heating device is only part of the probe and should be hotter than the tube it is heating up.

This answer says there are significant differences between Pitot heat systems, and some on the light aircraft are rather "anemic". Hence it may be that some models are heated and operate at much higher temperatures. There is also a phrase "plastic cover could melt" there. Plastic melts well over 150 °C.