In that case you could either do like robert said and take salt water from the tank to use in the bucket, or if it's a fallow tank with nothing to kill, put it in the tank, but I would drop the water temp down closer to room temp so it's not such a shock, then slowly bring it back up. And be prepared to pick up some salt water or salt mix tomorrow because if there is much die off, that water will need to be changed out asap.