I use Multiminer with my r9 290s on win7.
Should I add something like --temp overheat -- to my Scrypt or Multiminer will do it without my help when my cards are overheated?
You need to add these arguments under Settings > Advanced miner settings. Anything that you would normally use with bfgminer you can place there.
You can also use external tools such as Afterburner from MSI.