Couple of important questions!!! Please help!!!

I have my 2 grow cabinets in a shed on the side of my house and its getting really hot inside, which makes my grow cabinets hot, so what are ways i can keep the shed cooler? Im also having problems with some type of flying bug ive used sprays but i dont k ow what to do because i think theyre doing damage to the plants. Ill post pictures of the damages and the bugs later.
 
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