Technology is turning against me

At the same time that I'm having to muck about with the heating, I switch on the lights in the porch and get nothing but a blue flash. Naturally I think the fuse has gone and change it. Still no light - than I notice that the two halogen lights I have in there have exploded.

These lights are exterior grade security lights with halogen tubes so the cold shouldn't have affected them and they're in the dry. There's no way I could have fed more than the 240V mains power to them and I know not to handle them with bare hands when installing. So how do both of them explode when I throw the switch?

I've bought a fluorescent tube fitting. Another job for the weekend.