My new program at the gym is hard work and alot of interval training, and my heart rate is always above the 165 mark the whole session.... sometimes peaking to 180

Is this an issue? will this help my weightloss or hinder it?
I dont really understand what happens if your heart rate goes above the 'recommended' rate and if its a good thing or not?

Also when my heart rate is that high it doesnt bother me... i just want to do the right thing to loose weight!