In January 2024, Black Diamond published an interesting study about how different electronic devices that we might carry in the mountains affect avalanche transceivers.

It's definitely worth a read. From their blog post:

“Various electronics often found in the backcountry were used in our test, including smart watches, GPS watches, smartphones, two-way radios, action cameras, satellite communication devices, electronic airbag packs, and even a snowmobile. The searching transceiver was held at 50cm from the torso using a static tether to help maintain the appropriate distance. Each item was then placed in a normal use position as noted below.  

The goal was to determine how bad it might be to violate the 20/50 rule. To do so, many items were held closer than 50cm (i.e., heated gloves and smart watches). Each item was tested three times, and the average taken. We then calculated the reduction in range compared to a baseline with no other items present.”

“The takeaway here is that EMI is real, and it can have a significant impact on transceiver performance! And we can’t stress enough the importance of updating the firmware of your avalanche transceivers and electronic avalanche airbag packs.”

Here's a link to their blog post and the results.