need to monitor temperature of several devices

Projects General Guidance
1

Hi This is Riaz. I am using this forum for the first time and apologies in advance if i made any mistake.

so here is what i need , i need to monitor the temperature of 8 different refrigerators in a cell phone and i want to send some kind of alarm to the cell phone if the temperature goes below or above the certain range.
i need to know few things.
1- can i do it using arduino if yes what version should i use.? (i am thing about MKR1010).??
2-for 8 different locations ,will i need to use 8 arduino boards..??
3- is it possible to use single app(Blynk) to monitor the temperature from 8 arduino boars??

any suggestion or help is appreciated.

2

A temperature sensor needs to be wired to the arduino.
If you have all These near each other then one arduino.
If you have them in differedifferent buildings then it might be one per unit.
A couple meters apart is about as far as you would want to run wires

3

2-for 8 different locations ,will i need to use 8 arduino boards..??

Several DS18B20 one wire temperature sensors can be used on one wire to one Arduino board.

Here is one of many tutorials available on their use.

4

You might look at esp32 if you want wifi and mppt particularly if the fridges are too far apart to use a single board