I’m sharing these experiences so that we can learn from each other. I’ve enjoyed reading other discussions about insulin and what effect heat makes on it. Please not that what I’m sharing is anecdotal - not scientifically proven or even advisable. 
I’ll start back in 1999 when I was still on a pump. My family and I spent a few months in Nicaragua that summer. It was hot but we did have refrigeration where we stayed. I was worried about the insulin in my pump, though. I was surprised and pleased that I never had a problem - even the horribly hot day that we hiked all over the place in the sun.
In 2000 we lived in El Salvador for about 4 months - again, no air conditioning, but refrigeration for insulin. Still on the pump. Very hot. We spent days out in rather remote spots of the country - running small medical clinics (no, I’m NOT medical – just a helper) in parts that were deemed by the government as the most needy. So… we spent lots of time outdoors, though we were out of the sun whenever possible. Toward the end of this time, the one problem I had occurred - I became dehydrated. I had been feeling fine, but suddenly my glucose shot up and I couldn’t get it down and nausea quickly followed. I ended up in the local hospital on an IV for several hours. I think the dehydration issue did not occur because of not drinking enough on one day, but over weeks, a little at a time. But I haven’t tested that! No problems with insulin, though. After the IV did its job, all was fine again.
In both of these places I had a backup plan - places I could go for help that I already knew about. We had our own backup supplies as well as all the supplies I would need on a day-to-day basis. We also had access to clean water.
Back in 2010 we moved to PNG to work. The first thing we did was a cultural training course to learn the trade language (there are over 800 languages in our half of this island!!) and to learn how to understand this culture. A lot of hiking was involved, starting with short hikes but then progressing to 1 day hikes and then a 3 day hike. It honestly scared me because I had had bad experiences with lows in the past when I tried hiking with my husband and sons. But, again, we came as prepared as we could. This time we were armed with frio bags to hold the vials and pens, but I no longer used a pump. I managed and the insulin did fine. Following that was 5 weeks in the village - no electricity so no refrig. Fortunately for us, cell phone coverage had come to the country the previous year and so we had that for one backup. We also kept insulin at our school (about a 45 minute drive away) and more insulin at a home with refrigeration about 1 mile away from where we were staying in the village. The weather was hot and humid. Everything, including insulin, worked fine - too fine one day about halfway through when I went way too low and my husband had to help me. I kept my insulin in a string/mesh bag (let air through) in a shady part of the house where it got a breeze. I also drank lots of filtered water - like 3 liters each day - as I wanted to avoid another bout of dehydration and IV.
After these 5 weeks, we moved to where we are living now, up in the highlands at 5,000 feet elevation. We have a home with refrigeration and pleasant temperatures most of the time. It’s really not as much of a concern for insulin but we do have some days that are quite warm and I carry insulin with me wherever I go, so I always keep insulin in a frio bag, out of the sun if it’s not in a refrigerator. I don’t go out to villages very often, but when I do it’s been carefully thought through and there is an escape plan in mind.
My takeaways from all of this regarding hot weather experiences:
- Insulin is tougher than most of us realize. I think we all know that. But we still have to be careful – and wise.
- Backups – extra insulin you can reach or a plan for how you can get to insulin.
- When we’ve been in the village, our contact has sometimes been a radio and sometimes a cell phone. Another option could be a satellite phone, though you would still need a number to call for help and a way to let them know where you are, maybe a gps coordinate?
- I always keep insulin with me, even on hikes when I don’t expect to need it – for unexpected spikes as well as possible dehydration that will make my BG go too high.
- Frio bags – like to be kept in a breeze as well as out of the sun. That may be obvious to most. A backup to a Frio bag that I learned about was to take a small towel and wrap it around the vial or pen and set that in a bowl of cool water out of the sun where a breeze hits it. I haven’t tried this, but it makes sense and comes from experienced people living in PNG for a long time who have needed to keep different items cooler than room temp.
- On days that I hiked all day – I avoided boluses by eating protein only for breakfast and lunch. At night I could eat carbs and bolus because the short-acting/bolus would be out of my system by the time I was ready to walk. I also took less basal/long-acting. With a pump you might disconnect or just lower your basal. This minimized the amount of insulin working in my body during the hike.
- Take extra food, insulin, syringes, test strips, pump and CGM supplies, etc. But I think that’s obvious.
- Drink lots of water - and carry extra with you.
- Count the cost - as in I don’t go out to the villages these days without a good reason. But I’m happy that I can if there is a need.
Sorry this was so long! Many of you have probably had similar experiences - but I wrote this in case there was someone for whom it might be helpful. Thanks for listening. 
always! Definitely!