  We investigate the impact of photochemical hazes and disequilibrium gases on
the thermal structure of hot-Jupiters, using a detailed 1-D
radiative-convective model. We find that the inclusion of photochemical hazes
results in major heating of the upper and cooling of the lower atmosphere.
Sulphur containing species, such as SH, S$_2$ and S$_3$ provide significant
opacity in the middle atmosphere and lead to local heating near 1 mbar, while
OH, CH, NH, and CN radicals produced by the photochemistry affect the thermal
structure near 1 $\mu$bar. Furthermore we show that the modifications on the
thermal structure from photochemical gases and hazes can have important
ramifications for the interpretation of transit observations. Specifically, our
study for the hazy HD 189733 b shows that the hotter upper atmosphere resulting
from the inclusion of photochemical haze opacity imposes an expansion of the
atmosphere, thus a steeper transit signature in the UV-Visible part of the
spectrum. In addition, the temperature changes in the photosphere also affect
the secondary eclipse spectrum. For HD 209458 b we find that a small haze
opacity could be present in this atmosphere, at pressures below 1 mbar, which
could be a result of both photochemical hazes and condensates. Our results
motivate the inclusion of radiative feedback from photochemical hazes in
general circulation models for a proper evaluation of atmospheric dynamics.
