If your Apple Watch (first-gen) has issues, you might not need to pay for repairs if you're out of warranty. Seems in certain cases, the warranty period has been extended to three years from the original one year.
No explosions here
It seems the batteries in the earlier model have been known to swell/expand. Enough cases have emerged it seems, as Apple has made this extension. Usually the maximum extension for repairs is one year, on top of the standard 1-year Limited Warranty. This means that effectively the first-gen Apple Watch will have a three-year service warranty.
The first Apple Watch was introduced 24 April, 2015 but was replaced by the Series 2 last year. You can still get an original Apple Watch for a discount and in limited models. But if you have the dough, the latest Watch might be more worth your money what with the better water-resistance.
Another Apple Watch is due to be announced this year so you might want to save your money for the inevitable discounts that will come for the Apple Watch 2. Should a new model emerge, there's a likelihood the first Watch could be discontinued.
Check out our experience with the latest Apple Watch here.