I have 4 of the Kingbrite 240W V4 boards in my 5X5 tent and I've had no issues with heat. I also live in Canada (Eastern Ontario). It gets really hot here in summer, but the central air conditioning keeps the ambient house temperature comfortable anyway - plants or no plants. They're pretty bright, and the dimmer is like a dangerous weapon! Everytime I adjust those 4 dimmer knobs I run to check my watt meter. Right now in mid-veg I have them dimmed just under 60% brightness for my 4 plants - pulling a total of 550W from the wall and the drivers are pretty cool to the touch. Fully cranked, they pull just a bit under 1,000W and are much warmer. I learned not to crank it up all the way because my plants thought it was way too much of a good thing during my last flower run. lol