I have used epioens for 25 years. The main thing is to keep them out of direct sunlight. Other than that there is not much you can do about the heat. Do check with pharmacy they might have a few tips.
Storage info should be in the leaflet that comes with the pens, but I use Frio wallets to keep my insulin below 25 degrees, and anaphylaxis is one of the conditions listed on their website - presume that means epipens. They’re just activated with water, and work very well. They can be reused for quite a long time - the older they are, the longer they need to soak.
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