Some actives in skin creams require you to keep the product in cooler temperatures wherever possible. The easiest thing to do would be to pop it into the fridge.
But if you don’t have unfettered access to your fridge (for example, if you’re travelling or living with roommates) or you just can’t be arsed to travel back and forth to the kitchen everyday, there is one easy solution short of getting a mini-fridge.
Store your product in a thermos that has some tap water in it.
Your actives will have a better shelf life and stay effective longer through a solution that’s not only fully portable, easy to store, but also doesn’t depend on electricity.
Why this helps: A thermos (or vacuum flask) keep things cool, and regular tap water left in the thermos will always be a few degrees cooler than the outside environment – and most importantly, the thermos’ incredible vacuum and glass insulation will help it stay that way.
Get a steel thermos, because the highly mirrored (shiny) exterior will reflect external light and heat better than a matte or plastic thermos.
You can technically keep the thermos safely anywhere indoors, but I recommend sticking it in a dark place like a drawer or a box to minimize the effect of light and heat.
There are some size limits to using the thermos method. Because of the shape and size of most thermoses, you will probably only be able to fit smallish, elongated products like tubes or vials, rather than large jars and bottles. However, there are larger thermoses out there, in particular those that are meant for food (called a soup thermos or a lunch thermos). If you don’t want to buy a food thermos, a cheaper option is to transfer your product to one of those small plastic travel containers that can fit inside the thermos.
[TIP: Before you immerse your tube/jar in the water, make sure the your product cap or lid is tightly closed so that no water can taint your product. For this reason, its also best not to fully immerse the tube in water, but only fill it about halfway.]