Can someone explain how to understand the UV measure?

[alank73]

When you check details of steps I see the UV reading on ##minutes. How that translates on something useful?

 

[signal-2-noise]

How many minutes before your skin starts to burn?

And I found this...
How to prevent getting sunburned with the Microsoft Band 2 | Windows Central

 

[pedenske]

As found on my Microsoft health dashboard:

UV exposure (est)

This is the amount of time the Band detected UV exposure during your workout. Avoid skin damage from prolonged exposure by using proper protection (SPF 30+, hat, and clothing), especially at midday when UV is the strongest. UV exposure reminders are available on Microsoft Band 2 when the UV tile is pinned. Learn more about UV and how to wear your Band for accurate readings.