As long as the Quick-Play or Trap is activated in a chain, you may activate the card. If you allow Cold Wave to resolve successfully without chaining, then you cannot activate set cards, "play" cards from hand, or activate Continuous Effects that trigger.daivahataka said:I'd certainly agree with Chaosruler's post that you can't activate traps that were already set either as this would be effectively "playing them".
That was the Question we were answering, he'd asked about if you let it resolve first then try to activate cards which had already been set.masterwoo0 said:As long as the Quick-Play or Trap is activated in a chain, you may activate the card. If you allow Cold Wave to resolve successfully without chaining, then you cannot activate set cards, "play" cards from hand, or activate Continuous Effects that trigger.