Prep for hiking trip, MDI pens

My teen just let me know that between final exams and graduation (early June), he and three friends are going to go hiking for 2-3 days on the Appalachian Trail.  He said he was letting me know so that I could help him plan for packing what he needed diabetic-wise, but packing light and not letting insulin fry.  (He uses pens.)  I've handled hot vacations and temps before, but always with daily access to a new, fresh ice pack.  So, what all should I know/should Aaron know about prepping to hike for 2-3 in what could easily be temps in the 90s (F) and up?  (P.S. I am NOT a hiker.  Neither is my son.  His girlfriend is a hiker.  But she's not diabetic.)

I think it will be okay. Insulin lasts 2 or 3 days in a pump on hot days. If he can keep it cool the first day it might help it last another day or two.  If he is working hard he might not need much insulin. Make sure the girlfriend knows how to help him in an emergency.

I've done extensive trips with syringes, but not pens.  Had no trouble keeping insulin effective through a 2 week hiking trip down Baja coast of Mexico and another weeklong trip down into the Grand Canyon when it was hot.  Just kept the insulin in the middle of my pack, so it didn't get hot from the sun or my body temp.   If pens are more heat sensitive, look at an outdoor store for those ice packs that only activate when they are crushed.  A couple of those should keep insulin cool for the trip.

He needs to cut insulin way back and bring 3x more snacks and sugar than he thinks he'll need.  For hiking tubes of cake frosting are light and give quick sugar. Sugar packets are better than glucose tablets because they take up less space.  I've never had too much food on trips.  He should bolus less than usual for meals and be super conservative.  Typically on the first hike of the season I used barely any insulin the first few days, then it slowly goes back to normal after muscles get into shape and don't need so much glucose.  

He'll be fine... when I was 18 I worked as a camp counselor and led a couple weeklong hikes in Washington state.  I managed my diabetes okay and it didn't affect my ability to take care of the kids I was in charge of.

I've done some backpacking in the summer months before and had no problems with my pens. I typically try to keep them close to my water in my pack and easily accessible.