"There was a small fire in the garage during the team's private filming day," confirmed a team spokesman.
"The fire was quickly extinguished by the team, and circuit emergency services and medical teams attended immediately in support," they added.
"Three team members were taken to the medical centre for treatment and were released shortly after."
It is not currently known what caused the fire, which happened a day after the opening pre-season test came to a close.
The Woking outfit is one of three teams on duty at the Spanish track today, taking full advantage of the filming day regulations, the team having earlier tweeted video of its 2019 contender on track with one its road cars.