One symptom of a helium leak is that your iPhone might stop working: https://motherboard.vice.com/en_us/article/gye4aw/why-a-helium-leak-disabled-every-iphone-i

One symptom of a helium leak is that your iPhone might stop working: https://motherboard.vice.com/en_us/article/gye4aw/why-a-helium-leak-disabled-every-iphone-in-a-medical-facility https://motherboard.vice.com/en_us/article/gye4aw/why-a-heli... This happened also to the coworkers of a friend of mi e - occasionally everyone's iPhone in their office would stop working. Android phones still worked fine. Later (after this article was published) they found out there was an MRI machine downstairs.