the document you refer to specifies,
Operating temperature1
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23 to 113°F (–5 to 45°C)
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which indeed is a normal temperature
>>> I read the temperature with SNMP and the values are around 70 ° C. <<<
imaging you walk into an equipment room and the temperature in the room is 70 ° C !!!
my guess is you are doing something wrong! 70 ° C is quite hot for operating temperature
more likely this temperature may be 70 ° F instead of ° C.