# A flaw in logic

OK, so I’m going to be starting pumping in a few months, but there seems to me to be a flaw in the logic of pumping. Obviously there is some solution that I can not see, so I was wondering if any of you could help me out?

Insulin needs to be stored at between 0 and 28 degrees Celsius, or it gets damaged and begins to lose its potency.

The human body runs at 37 degrees Celsius.

If you keep your pump in your pocket, doesn’t it get too hot and damage the insulin?

I actually had a pen get cooked in my pocket today because I forgot to take it out, when I remembered and took it out the insulin was already cloudy and full of floaters. This wasn’t the first time this has happened to me either.

why won’t the same thing happen to the insulin in a pump if I keep it in my pocket?

I’m going to ask my pump educator the same thing when I see her next, but I was wondering if anyone could help me out in the mean time…

I wouldn’t put it in your pocket. Yes, your body temperature is 37 degrees celsius, but your pocket is pressed against your skin and the exterior cloth retains heat (that’s the main purpose of clothes!), so the temperature within your pocket may actually be higher than body temperature. For my son, we actually have a pocket sewn to the back of his shirt, which we make sure is loose and not tight to the body, which means there’s air circulating between him and the pump (and there’s a fairly thick cloth shield that further insulates the pump as well). This means we can keep the same cartridge full of insulin in my son’s pump for up to three days without any concerns, but we don’t try to go any longer than that. Pity, because it wastes a lot of insulin… he only uses very tiny amounts, no more than 11 or 12 units a day… but it’s still worth it. When ambient temperatures get higher in summer, we probably will put a sleeve around it - you can buy insulating sleeves for some pumps, too. Or you might consider getting a fanny pack or a belt hook. There are a multitude of options that expose it to less heat than your pocket.

interesting to hear, the pen that got heat damaged today was novorapid, and all i was doing was sitting down inside for a couple of hours.

maybe the insulin was contaminated, or getting on the old side, i prob started using the pen over a month ago…

but then again i’ve had it happen to me a couple of times before…

me too,it’s pretty hot around here,hot as in 35 degrees outside,even worse.
never had a problem with bad insulin in my pockets,I always put them in my pockets in school so whenever I eat something I can directly take it,my educator told me that I shouldn’t,but it pretty much works for me

What may be happening is that you had the same pen cartridge in the pen in your pocket more than 1 day. The effects are cumulative after all, and it really doesn’t matter how the insulin gets heated up nearly as much as it does how warm it got and for how long until it gets used.
I’ve been pumping for 16 years and haven’t had insulin go bad in the pump that I can tell you about. Of course I also don’t keep it in a pocket most of the time, the only real reason I do so is for job interviews where I don’t want to advertise my diabetes, then I carry it in a T-shirt pocket as long as I must.

I carry my pump in my pocket (or otherwise right next to my body) almost daily and have had no problems. I have Humalog in my pump. It doesn’t really make sense to me, either. When I first started the pump I asked the trainer this same question and she just said it wouldn’t be a problem.

I’ve not had any problems with insulin going “bad” in the pump itself… I pretty much only wear mine in my pockets.

i’ve been t1 for 50 years, pumping for 12 and i’ve never had a problems with insulin. i’m convinced the worries about overheating are exaggerated. the stuff is far more robust than you think. i’ve had extended trips to some freakishly hot places (Iraq among them) and i’ve never had a problem. (i don’t take special measures either. i simply toss vials into my bag and go). it takes about 8 days for me to exhaust a reservoir and i never cut it short. my numbers are always good. so … short of dropping a vial into a pot of boiling water i can’t imagine it being a problem.

The pump itself may provide some protection against body heat since the insulin is in a cartridge which is then placed within the pump which provides an additional layer.
When I was pumping, I always wore it right against by my body and had more problems with the buttons (or the rubber/plastic thing) coming off of them than any damage to the insulin.

thinking about it more though…with the tubeless pumps they are always right next to the body and with tubed ones, even if you place the pump outside the body at least a portion of the tube filled with insulin is next the body, though it probably helps that it doesn’t stay there that long.

For an official answer though I would ask the pump and/or insulin manufacturers directly…I feel like it is something the pump manufacturers would have had to consider esp. to get gvt. approval (e.g. FDA in the US)