Bolt Device disconnect With Cloud automatically

For My Last Project , I have connected My Bolt Module with Power bank and Put it into my freezer for getting temperature values but after every 10 minutes bolt module disconnect with cloud and after that bolt module got switched off. so, is there any solution for that, ???
why is it happen?

Although ,I Dont have Enough Experience to answer this but, I think You should not put the module in the freezer because these chips are not meant to work in extreme Conditions , As per my opinion these chips are only for Learning and educational purposes , or May be the power bank in not meant to work in extreme conditions.

I’m not sure if putting the module into your freezer is a good idea. Although ESP8266 is expected to be in working conditions above -40C, that’s just a standard and there are other components in your circuit that might get short-circuited. Again, your loss of connection might be due to interference in the line of sight with your router.
The bolt module might have been programmed to shut down if there’s no connection to the cloud (power saving modes), but I haven’t verified that.

Actually , i have tried again and again so i got some results in graph that temperature is never goes below 0C it never goes in minus and bolt module goes shutdown but power bank never turned off it is always,
how should i have to do this capstone project ?? Any Suggestion??
if bolt module goes turned off than how can i measure proper result??

LM35 generates a low voltage (ideally 0V) at 0C and so, you won’t be able to obtain negative temperatures directly. The power bank staying on has nothing to do with a wifi connection. Your ESP module(bolt module) probably puts itself into shutdown(power saving) mode(meaning it does not consume power from your power-bank) when it cannot connect to an available network(your router, in this case).
I’d suggest you increase your threshold value close to room temperature, slightly below it by 2-3 degrees and then take it near your refrigerator or something.

@choksidhrumil2000 I think this is because the Bolt Device is unable to connect to the WiFi network when it is inside the freezer. Did the device switch off or was the light blinking on the device?
Also, putting the device directly inside the freezer is not recommended. You can put the device inside the chiller section of your fridge.

After some time passed led starts blinking and after that its off and after that Device also Switched off

sir i have tried many times in different way i have tried where powerbank is outside the freezer and bolt module is in side the freezer but after 5-7 mints it goes disconnected and bolt module goes offline after that it switched off
how can i get my results

You don’t have to put the module inside the freezer at all. You can place it outside. There’s no way you can reach so low temperatures anyways. I believe it’s the logic in your project that matters. So changing the temperature range should be acceptable as long as it is modifiable to work for real test conditions.
If you are not satisfied with that, you can try connecting LM35 to the bolt via female-male connectors and place the sensor inside the freezer instead of the entire module.

@choksidhrumil2000 You do not have to place the Bolt device inside the freezer at all. As @pankajkumar.p has mentioned, you can place it outside also to monitor the temperature.

probably there is a fault with the cable, or the device is damaged due to unbearable cold conditions.