There is a warning email sent when the temperature gets too hot. It spits out a message like
System Notification from orc (OVER_TEMPERATURE_WARNING!!!) EMERGENCY
Looks like 'over temperature' is the only thing you'll be able to get:
$ snmpget -m all toaster public envOverTemperature.0 enterprises.netapp.netapp1.sysStat.environment.envOverTemperature.0 = no(1)
Looking at v1.5 of the MIB (which AFAIK is the latest), there's nothing that'd give what you'd want. 'bit of a shame too, given that even the FC9's are collecting thermal data -- would make a great mrtg graph..
..kg..