What are heat detection sensors and how can they cause a speed error? From this news article on Saratov Airlines Flight 703:


  A report handed down by Russian investigators has blamed human error for the crash of Saratov flight 703, saying the pilots didn’t switch on the heat detection sensors on the plane.


Heat detection sensors sounds wrong as cause of de-icing failure.

Is it a bad translation of the sensor's name? What would be the correct name? Else please explain how the failure to turn on a heat detection sensor cause icing speed error detection.
It seems that the pilots didn't activate pitot tube heaters but the investigation is not completed yet.

"Pitot tube, also known as Pitot probe, is a flow measurement device used to measure fluid flow velocity."

So detection sensors in your question refer to pitot tubes and failure to turn on their heaters in icing conditions can cause incorrect airspeed indication. This in turn may lead to incorrect decisions from pilots or autopilot.