In another post I mentioned that laser efficiency improves with lower temperatures and this is indeed the case but we are talking about small gains and a lot of expense to reduce temperatures below ambient (room temperature).
Operating a laser at room temperature or above is how they are designed to be run, running at ultra low temperatures can cause it's own set of problems unless you are fully aware of dew points and the machinery used.
Please don't think the "magical" figure of 8 degrees is set in stone, it's not, it is simply a figure where improvements can be found but to do so reliably can cost in excess of £1000 and for the day to day user may well be a waste of money.The gains will not pay back the investment in any short to medium term use.
Hope that clears up the temperature information
best wishes
Dave