Smart watch notifications when doing maintenance work

I'm looking to improve the notifications experience for a heavy duty smart watch that assists people working on maintenance activities in a factory environment (e.g. the room they are in might be getting too hot).

There's been some feedback from users that the notifications can be distracting at times, especially when working in groups as all the staff get the notified at the same time. There's also risks of it distracting the work when using equipment with the same hand as the wrist the watch is on.

What should I be considering when improving this experience? The elements that could possibly be used are sound, vibration and the screen itself.

Note: This solution it's not meant to replace any existing safety systems, but to complement them. The solution is compliant with safety standards and has been running on the customer's site for a few months now. This question is asking how to improve the existing experience as we get feedback from its users.