The opening day of the Chinese Grand Prix has been heavily disrupted by persistent thick cloud that prevented all but a few minutes of on-track running over the two practice sessions.
Low cloud, rain and smog in Shanghai meant that the medical helicopter at the circuit was grounded due to the fact it would be unable to land at the nearest hospital, some 38km away, if there was a medical emergency.
After an initial delay in the morning, some drivers were able to complete around 20 minutes of running on intermediate tyres in Practice One before the red flag was thrown again, while no running whatsoever was completed in Practice Two.
The first practice, which featured only 88 laps from all 20 cars combined in damp conditions, was topped by Max Verstappen, comfortably ahead of the Williams pairing of Felipe Massa and Lance Stroll.
The last time an entire session of a GP weekend was cancelled was in 2015, when stormy weather prevented FP2 taking place at Austin.