I'm doing a loft conversion which involve using metal joist hangers
(instead of the traditional joists laid onto the inner leave of a
cavity wall) and I am about to fix the chipboard on top of the
structure, but but I've realized that I have probably omitted some
treatment for possible cold bridges from the end of the joists (the
ends fixed on the joist hangers).
In fact I want as well apply some internal insulation using Celotex
boards fixed internally on the whole 4 walls including the loft space.
Clearly I cannot apply such insulation behind the joist hangers
therefore cold bridges are going to be an issue.

What can I do to eliminate/attenuate such cold bridges?

I am thinking of using some flexible insulation like Airtec (airbubbles
plastic stuff similar to that used in packaging with aluminium layer on
both sides) wrapped around the joist hangers and joist ends as well.
Will it work? Or will it make thing even worse?
Any suggestion appreciated.

Thanks

Alex