Which temperature element is causing MacBook to stop?
No. Apple doesn’t publish firmware code and you’d have to reverse engineer several components including the on die cpu sensors, the discrete sensors, probably sensors on storage and possibly dozens of sensors within the battery cells. 

Since the MacBook have no blowers, on a practical level, you can prop it up on a stand and ensure airflow is good and optionally ensure cool air surrounds the device to reduce internal temperatures. The whole case is a heat sink and radiator, so you can dramatically cool it with an elevated stand and/or cool airflow. 

If you have any coverings or cases on your Mac - absolutely remove them since a thin gap of air between the metal and plastic is a great insulator just like a blanket would be.

Outside in the sun or even with shade, you can have several additional problems:


sunlight on the black screen will overheat it dramatically and light on the rest of the case is less than ideal. 
getting cool air will be hard or impossible