Hello,
This project is as you say easy to implement, for person with experience with arduino.
As far as I understand you need the arduino nano to work as a sensor hub for the 5 sensors (4 temp. and 1 heart rate).
Since the sensors and the bluetooth module are with already done libraries the work is only matching the already done modules. This however is not very hard. It will take some time to test everything and write a well done code, but I see no problems stopping the development process.
I am proposing every step of the project with the price for it, if you don't need something it' no problem to remove the task from the project milestones.
I can create the prototype and send it to you, or guide you through the setup of the wires, and uploading the code.
If you have any questions please dont hesitate to ask.
Best Regards,
Mihail Vrachanski