Just write a G Code program and save it as your spindle warm up.  That is how I have all of our spindle warm up programs here in the shop.
Figure out a time that your spindle warms up to that 85 deg mark and let it be that. 
Use your own Spindle RPM in place of S
G04 P###  Adding a "." will make it read seconds instead of milliseconds (from my experience).   G04 P1.0 = 1 Second

(Spindle Warm Up)
S1000
G04 P180.0 (Dwell for 3 Minutes)
M5
G04 P60.0 (Dwell for 1 Minute)
S1500
M3
G04 P180.0
M5
G04 P60.0
S2000
M3
G04 P180.0
M5
G04 P60.0
ETC......
ETC....
M30

NICE!
Thank you Cbyrdtopper!

I just load the G Code File and run it from there.
But you can make a custom button if you want to do that as well.
Save your Spindle warm up program as O9001 (as an example).  Save it in the "Subroutines" folder in the Mach4 Directory
Make a button on your screen and in the button's Clicked Script put following code in:

local inst = mc.mcGetInstance()
mc.mcCntlMdiExecute(inst, "M98 P9001")

The only thing you need to do different in your spindle warm up program is to have an M99 at the end instead of an M30 so it will return to the button press and stop from there.  Weird I know, but that is how it works for me when I run sub programs from a button press.



Or just save it and run it is as a G Code file.

Understood.... mostly.
It'll take me a bit to navigate but I'll post an update once sorted.


Thanks again Chad.

This is gonna sound ignorant, but.....
Does the initial spindle startup S1000 not need a prior M3 command in this context?
Is there a function of the interface that supersedes this need?

Scratch that.
This is perfect.
Much appreciated!