  Aims. Continuing the systematic determination of the electron temperature of
H II regions using the Balmer and/or Paschen discontinuities by Guseva et al.
(2006) we focus here on 3.6m ESO telescope observations of a large new sample
of 69 H II regions in 45 blue compact dwarf (BCD) galaxies. This data set spans
a wide range in metallicity (Zsun/60<Z<Zsun/3) and, combined with the sample of
47 H II regions from Guseva et al. (2006), yields the largest spectroscopic
data set ever used to derive the electron temperature in the H+ zone. Methods.
In the same way as in Guseva et al. (2006) we have used a Monte Carlo technique
to vary free parameters and to calculate a series of model spectral energy
distributions (SEDs) for each H II region. The electron temperature in the H+
zones was derived from the best fitting synthetic and observed SEDs in the
wavelength range ~3200-5100A, which includes the Balmer jump. Results. On the
base of the present large spectroscopic sample we find that in hot
(Te(H+)>11000 K) H II regions the temperature of the O2+ zone, determined from
doubly ionised oxygen forbidden lines, does not differ statistically from the
temperature of the H+ zone. Thus, we confirm and strengthen the finding by
Guseva et al. (2006). We emphasize that due to a number of modelling
assumptions and the observational uncertainties for individual objects, only a
large, homogeneous sample, as the one used here, can enable a conclusive study
of the relation between Te(H+) and Te(O III).
