With the hot season coming, it is not always easy to protect your packed lunch from the heat. Not everyone has access to a fridge at work. You might even need to leave your food in your vehicle.
The best way I have found to solve the problem without having to buy a fancy cooler is to place your drink in the freezer overnight and use it as an ice pack to keep your packed lunch cool. By the time you get to have your lunch, your bottle will probably be ready to drink too.
I used to get a brand new plastic bottle at the beginning of the week and reuse it the other 4 days. Then I found out that stressed plastic (i.e. re-used plastic bottles) – release toxic chemicals….. You can find plenty on that topic on the Internet so I won’t go into details about the danger of reusing plastic bottles.
Whatever type of bottle you use to carry your drink, make sure it is not filled to the brim because water expands when it turns into ice.
You might also want to use a few layers of newspaper to wrap your food and “home-made ice pack” as newpaper is a very good insulator.