I was on vacation July 1-8; left on the first and came back to Chicago on the 8th. I reduced my Lantus from 8u (which I'd been taking for the last week of June) to 6u, which I took on the evenings of July 1-6. I took 4 1/2 u Lantus on the evening of the 7th because the 8th was a fast day.
This was my first vacation with diabetes in which I managed to avoid severe, symptomatic, scary hypoglycemia. I did run a lot of lows in the 40s, but I didn't have any lows that made me woozy, panicky, or disoriented, and I didn't go lower than the 40s.

This was also the first time I tried packing a sensor. I've had two vacations in the past where I had been wearing a CGM; in one, I just left the CGM at home and took a sensor break, and in the second I changed sensors right before leaving. This time I took a sensor in the bag but not the box and put it in with my clothes. When I got where I was going the bag looked pretty beat up but the sensor looked okay, and two days later I changed sensors. It performed beautifully. Unfortunately, I'd forgotten to bring scissors to cut my hairs before applying the sensor, and it was a really hot week, so after a week I pulled the sensor because I didn't think it would stick on much longer. But it worked just fine. I will be less hesitant to pack sensors in the future.

One thing I must've done a bad job packing: pen needles. I currently use syringes for the Novolin R and testosterone and pen needles for Lantus. That means that on an 8 day vacation, I expect to use 7-8 pen needles and anywhere from 20-50 syringes. So I packed a box of a 100 syringes and counted out ten pen needles which I put in the box. Well, I guess that's not a good place to put them, because I had trouble finding the darn things. In the end I only could find five pen needles. I reused one of them and did the last Lantus shot by syringe. I guess if you have enough syringes, not having pen needles isn't really such a big deal.

I recently read a study that's made me think about how I store my insulin, even those vials in use. This study looked at Regular and 70/30 insulins made my Novo, Lilly, and Biocon (Biocon insulin is not available in the US and is a U-40 insulin for sale in India). So that's 6 types of insulin. They stored them in unopened vials in 5 different storage conditions (now we're looking at thirty different situations). They wanted to compare how the storage conditions affected degradation of the insulin over a period of two weeks, and over a period of one month.
They injected the insulins into rabbits to see how much the insulin lowered rabbits' blood sugar after being stored in different ways. The rabbits started out with blood sugars in the range of 100-108 mg/dl (apparently that's normal fasting blood sugar for rabbits). The insulin then made them hypo. It lowered blood sugar into really tight and predictable ranges with little standard deviation. It lowered blood sugar significantly less when the insulin had been stored at temperatures of 32 and 37 degrees Celcius (89.6 and 98.6 degrees Fahrenheit), as compared to when it had been stored at temperatures of 5 to 26 degrees Celcius (41 to 78.8 degrees Fahrenheit).

This strongly suggests, at least to me, that a person who carries around his short acting insulin during hot temperature days should carry it in something that will keep it at a temperature that is at least below 89 degrees Fahrenheit, lower if possible, unless the insulin will be used up in less than a two week time period. The Frio may be a good idea.

The full text of the study is available here: http://icmr.nic.in/ijmr/2009/august/0910.pdf