# Closed loop dealing with the extreme heat



## SB2015 (Jul 14, 2022)

I am using a closed loop system, (780G) which should automatically adjust things enough for me to avoid hypos.  We have no input to our basal rates on the closed loop which is checking in with the sensor every 5 minutes and making adjustments. (unless we switch to manual). However in the past weeks with this heat I have had many more hypos Including some at night.  
Having checked in with my DSN I have now: 

Raised my target level from 5.6 to 6.7 (reduces the amounts in correction doses)
Changed my increments from 0.1 to 0.025 to allow the pump to make smaller basal adjustments.
So far so good.  No hypos and still a good TIR.
I hope that  this might be of use to others.


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## Lucyr (Jul 14, 2022)

Sounds good but did she have any idea what the cause might be? Is the hot weather / dehydration making the sensor read higher than you are, or making insulin work quicker than your pump expects or something else?


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## everydayupsanddowns (Jul 14, 2022)

Yes my Control IQ has been struggling to keep up with the increased insulin sensitivity in the warmer weather too.

Still performing better than I would on my own, but not catching things as usual. Plus, of course you kinda get used to relying on the system sorting things out in the background, so have to click back into making the preventative measures up front.


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## Rob Oldfield (Jul 14, 2022)

Do the loop systems have any kind of thermometer built in?  Might be something for the future?


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## helli (Jul 14, 2022)

Rob Oldfield said:


> Do the loop systems have any kind of thermometer built in?  Might be something for the future?


The loop is software based on CGM readings. I understand some CGMs do detect body temperature but I am not sure that rises much as the ambient temperature rises.


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## trophywench (Jul 14, 2022)

Tee hee.  I'm not at all amused by any of you finding glitches, I'm not that nasty (with most people) - BUT when did the word assume not = making an ass out of you and me?

It's very new technology - and you are Beta testing it!


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## trophywench (Jul 14, 2022)

Oh by the way - do get it sorted before I'm due my next pump, please!


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## Matchless (Jul 14, 2022)

I am not on a closed loop but FSL has always giving me high reading all of a sudden when having a hot shower in the colder months of the year and when i sit in the sun in the summer (like now ) for 15mins it shouts out to high on my xdrip app.so it must have a thermometer .obviously its not high its a error 10mins later its back down.


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## trophywench (Jul 14, 2022)

I've had it tell me it's too hot to tell me my BG when I scan it, but it's been OK later when no longer in the noonday sun - on hol from tomorrow so I'll see cos there's no way Pedro I ain't sitting in the sun, except literally at noon!


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## SB2015 (Jul 14, 2022)

Lucyr said:


> Sounds good but did she have any idea what the cause might be? Is the hot weather / dehydration making the sensor read higher than you are, or making insulin work quicker than your pump expects or something else?


I already knew what the cause was, with the high temps causing an increase in sensitivity.  

On my old pump I would have set a reduced basal rate and also taken a bit off my boluses in this heat.  With the closed loop the pump with the sensor is making the decisions about basal for me, and it needed a bit of help to address the change in sensitivity.  Like  @everydayupsanddowns indicated it is easy to forget how much I used to have to do before looping and easy to take the loop for granted.  

I do ensure that I keep hydrated in this weather so that definitely helps with any sensor readings.  I have my sensor in my upper arm, and I am aware that there are times when that is in full sun, and I don’t want to wear sleeves in this heat.  I just tend to walk on the shady side of the street.

All good today after the changes I have made


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## everydayupsanddowns (Jul 14, 2022)

trophywench said:


> cos there's no way Pedro I ain't sitting in the sun, except literally at noon!



Mad dogs and Englishmen?


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## trophywench (Jul 14, 2022)

Well the risk of meeting any mad dogs is very slight, so slight in fact it's completely safe in my opinion to ignore that risk.

However ......    

Note to self - Must remember to put my watch on every day on hols - always useful if people ask if you have any white bits !


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## runner (Jul 18, 2022)

I have a DexCom sensor and have been looking at pumps. Consultant is happy to refer me for one and I’ve been researching pumps. Is a closed loop system that you mention a pump linked to s Ensor or a pump that adjusts automatically?  I’m finding the heat increases my BG!


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## Bruce Stephens (Jul 18, 2022)

runner said:


> Is a closed loop system that you mention a pump linked to s Ensor or a pump that adjusts automatically?


Yes, they're a pump, a CGM, and an algorithm of some sort using the CGM readings to control the pump. The algorithm may run on the pump or on your phone.


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## runner (Jul 18, 2022)

Bruce Stephens said:


> Yes, they're a pump, a CGM, and an algorithm of some sort using the CGM readings to control the pump. The algorithm may run on the pump or on your phone.


Thanks.


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## SB2015 (Jul 18, 2022)

Hi @runner the companies use different terms to describe the systems that are available.
Basically you  can use a pump

Stand alone without sensors
Along with sensors so that the pump will give alarms and also insulin suspend on lows
You set and adjust the basal programmes and can make temporary adjustments as necessary
In a closed loop
The pump controls the basal rates and makes adjustments to this by checking in with the sensor  every 5 min.
This thread gives a comparison between the different pumps.  At present there are two options T-slim with Dexcom sensors and Medtronic 780 with Guardian sensors.


			https://forum.diabetes.org.uk/boards/threads/cgm-flash-comparison-chart.101117/#post-1184504


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## helli (Jul 18, 2022)

@runner the other thing to consider with pumps is what pumps are approved by your CCG. Your CCG may offer a pump which is compatible with Dexcom or they may not. Before too much research, I strongly recommend asking your consultant what pumps would be available for you. Otherwise, you risk raising your hopes for an all singing and dancing closed loop system with your Dexcom to then discover the only options available to you are not compatible with Dexcom and not possible to closed loop with any CGMs.


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## Bruce Stephens (Jul 18, 2022)

Such limited choice in pumps is something else that Partha Kar is unhappy with and working to resolve.


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## runner (Jul 18, 2022)

helli said:


> @runner the other thing to consider with pumps is what pumps are approved by your CCG. Your CCG may offer a pump which is compatible with Dexcom or they may not. Before too much research, I strongly recommend asking your consultant what pumps would be available for you. Otherwise, you risk raising your hopes for an all singing and dancing closed loop system with your Dexcom to then discover the only options available to you are not compatible with Dexcom and not possible to closed loop with any CGMs.


Ok thanks.


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## Inka (Jul 18, 2022)

The Dana pump can be looped with Dexcom too @runner @SB2015


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## everydayupsanddowns (Jul 18, 2022)

And the Medtrum ‘nano’ too I think?


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## Saoirse (Jul 18, 2022)

Inka said:


> The Dana pump can be looped with Dexcom too @runner @SB2015


This is true of course, but just worth noting that the T slim loop has inherent software from tandem which allows looping.  Dexcom and dana are loopable together but need another bit of software on a phone- this is either something you put together yourself via diyaps, or with camaps which you need to pay for.


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## SB2015 (Jul 19, 2022)

Thanks for the additional info @Inka and @everydayupsanddowns


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## helli (Jul 19, 2022)

everydayupsanddowns said:


> And the Medtrum ‘nano’ too I think?


Confusingly, the latest Medtrum pump and CGM are both called “Nano”. I wouldn’t say they provide full Closed Loop (I still define a basal profile) but they do talk to each other so that the pump suspends basal when the CGM detects low levels.


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## everydayupsanddowns (Jul 19, 2022)

helli said:


> Confusingly, the latest Medtrum pump and CGM are both called “Nano”. I wouldn’t say they provide full Closed Loop (I still define a basal profile) but they do talk to each other so that the pump suspends basal when the CGM detects low levels.



FWIW the Tandem tSlim also bases its hybrid closed loop adjustments on the profile(s) you set up. This ability to manually adjust the closed loop’s decisions rather than surrendering to a predefined algorithm was something that actively appealed to me


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## SB2015 (Jul 19, 2022)

everydayupsanddowns said:


> FWIW the Tandem tSlim also bases its hybrid closed loop adjustments on the profile(S) you set up. This ability to manually adjust the closed loop’s decisions rather that surrendering to a predefined algorithm was something that actively appealed to me


That does seem to be a bonus with the t-slim.  I shall be doing a pros and cons list nearer my next change over.  I suspect that avoiding another switch of pump if possible might move up my list a fair way, but who knows what will be available by then.


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## multimummy (Jul 24, 2022)

SB2015 said:


> I am using a closed loop system, (780G) which should automatically adjust things enough for me to avoid hypos.  We have no input to our basal rates on the closed loop which is checking in with the sensor every 5 minutes and making adjustments. (unless we switch to manual). However in the past weeks with this heat I have had many more hypos Including some at night.
> Having checked in with my DSN I have now:
> 
> Raised my target level from 5.6 to 6.7 (reduces the amounts in correction doses)
> ...


Thanks. I don't use a closed loop complete system as yet, still on a 640G (??) pump from Medtronic so my Medtronic CGM suspends when heading towards hypo but doesn't give the heading to hyperglycaemia corrections automatically.  I've had to set a reduced basal schedule in the recent very (for the UK) hot period.  Historically I know hot weather, particularly of sudden onset, sends my BG into my boots! There was a memorable occasion when I was a student when I apparently "meowed" at my land lady - thank goodness she picked up on what was up and took me to A&E!!  (This was well before the days of pumps and CGM!) When I get my next pump due to warranty expiry it will be a 780G, so will remember your tip.


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