Pests or infection?

[Leafmite]

That certainly does look like cold damage. Cold can damage plant cells or, if that doesn't happen, it can stress a plant quite badly and make it vulnerable to disease. If there is cell damage, there isn't much you can do but hope that the damage is all in the leaves and that new growth is healthy. If it is an opportune infection, you can usually fight this and win.
I have had plants (including the fruit trees) get hit by cold and lose all the leaves or, in the case of veggies, look terrible but then recover. Good luck!