The recently proposed constructive approach to nonperturbative QFT, based on modular localization, is reviewed and extended. It allows to unify black holes physics and H-temperatures (H standing for Hawking or Horizon) with the bootstrap-formfactor program for nonperturbative construction of low dimensional QFT. In case of on-shell particle number conservation, the equations characterizing the modular localization spaces for wedges are Bethe-Ansatz equation in the form as recently obtained in the treatment of factorizable models.