During the Summer it can be a struggle to find a way to keep things cold.
I like to go hiking a lot… Hiking uses a lot of energy & can get unquestionably warm. This is why I like to carry water & food with me. This stuff is tough to keep cold the entire time though. I keep it wrapped & I keep it in my backpack to try & shade it the best that I can. I make sure none of the coolness escapes from the food or the drink by wrapping it. I try to keep it cool the same way I keep my apartment cool in the summer. I have air conditioning but I like to save energy & the cool air by closing my shades, but by closing the shades & my backpack, I am not allowing any of the cool air to escape or be heated by the sun. I like to make sure that my apartment is respectfully insulated. This helps by not allowing the cool air to leave my apartment in any spot. I try to keep my food insulated with aluminum foil or a cooler pack. I also avoid using extra heat, when I am hiking I try to stay out of the sun as much as possible. These two things could go hand in hand. When trying to keep things cool there are particular things you must regularly do no matter what it is… Keeping your apartment cool is the most substantial so that you do not waste energy on air escaping your home, then your apartment will get moderate air into it & your Heating & Air Conditioning system will work harder to put the cool air back into it.