The Fe8 molecules have spin S=10 and high magnetic anisotropy that corresponds to a 27 K energy barrier between spin projection S_z=±10 and S_z=0. These molecules show magnetization jumps at regularly spaced steps in the applied magnetic field. During those jumps the molecule decays to the ground state and produce heat bursts, which, in principle, could lead to avalanches. We report spatially resolved, time depended, measurement of the magnetization jumps of a Fe8 single crystal mounted on a microscopic Hall bar array. No evidence of magnetic avalanche where detected. The time difference between tunneling events experienced by different sensors can naturally be explained by miss-aliment (2mm) of the sample with respect to the center of the coil. This result strengthens previous suggestions that the heat bursts is due to electromagnetic radiation emanating from the nano-magnets during tunneling.