I wouldn't worry about heat at all with LED and I'd worry more about getting a panel that's actually drawing its rated power.

If it advertises 700w and it draws 350w at the wall you're being scammed.

And it appears a HUGE majority of panels are being made like this by the Chinese and they're not telling anyone until they get called out on it and lose face (typical Asian business practice.)
khyberkitsune Reviewed by khyberkitsune on . LED Grow Light Dectectable? ok i have a question about the led grow lights. Can these be detected by police helicopters? After all the research i've been doing it seems they can't as they dont let of hardly any heat but just want other ppl's opinions. Also i've noticed alot of debate on if these work or not as some ppl say the do and others say they don't. there are recent LED's out called ISIS FX1, FX2 and FX3 The FX3 700 watt panel aparantly is the same as using 2000w HID and from the picture guides i have Rating: 5