is your question still unsolved for you?
What version of NX CAE do you use?
What kind of Nastran do you want to use?
I did check my NX CAE (using NX CAE 8.5.2, for NX NASTRAN) in standard options for a solution
Analysis Type: Structural
Solution Type: SOL 101 Linear Statics - Global Constraints
and I can find the menue entry "Initial Temperatures" as expected in
Toolbar "Advanced Simulation"in
group "Simulation Object Type".
I also can find "Temperature Pre-Load"
(see Picture for both)
May be its a problem with roles. I use the role "System default => Advanced with full menues". What kind of configuration role do you use?
May be there is a work-around for your problem:
To set uniform constant initial temperature for the complete model you also can use the entry
in Solution options
General "Initial temperature default (TEMPD)"
(see picture), but may be the entry is missing in your environment, too.
I hope, You have a way to solve your problem. Good luck!
And tell me, if you could cope with it.
Edit: As I do not use NX10 I can't check if my model worts with NX10 furthermore, but did you read the following entry?