Can I re-attach my digitizer with heat?

I just dropped my phone on the kitchen floor - ouch!

On first inspection I thought my screen had cracked in the top left hand corner but no, it’s fine. There is however some damage - the digitizer and glass have started to part company and there is a ‘rash’ of tiny ‘bubble like marks’ between the two.

I ran my thumb across the area in an attempt to re-stick the glass, no good. Then I warmed it slightly with a hair dryer and tried again. There was an immediate improvement but the damage is irritatingly still visible.

I’m hesitant about getting the phone too hot. How far should I go? Am I likely to fix the damage completely or could I make matters worse.

Although I’m fairly competent at repairs having changed both batteries and screens on iphones in the past I’m hesitant this time. The reason is that I have phone insurance, courtesy of my bank this time, so for a £75 policy excess, I could get the phone replaced with a refurbed one. I don’t, therefore, want to cause obvious evidence that I’ve been messing too much with it! Nevertheless everything else is working so I could save myself a lot of hassle.

What should I do?