If you don't have a fridge you could ask for some ice in a bucket & keep them in a small plastic container in the ice. I also have a frio cool bag (search in google for their email address) I've had mine years and it great for travelling. It has small crystals in and when placed in water (colder the water the better) they expand and the bag becomes like jelly, it keeps insulin cold for 48 hours. There are different sizes, I got the small one which was about 10 english pounds, but I remember originally I got the english contact address from a site in America, you may even get one on ebay, never looked to see if they are available on there. Failing that your pharmacy may know the address. Any problem let me know & I will see if I can find it again for you. Plus it has a duo purpose, if you have a hangover or too much sun, it opens out and you can place it on your head.
ps it takes about 2 weeks to dry out when you get back home.