thermal fluctuation and hydrodynamic interaction in fix srd

I read stochastic rotation dynamics dose not need thermostat,
because both thermal fluctuations and hydrodynamic interactions are taken account into this model.
If i use fix srd command, i no longer need a thermostat??
Thanks in advance

Samira;

Fix srd has an optional thermostat keyword, but it is up to you
and your model whether you want to use it or not.

Steve