McLaren's Lando Norris in pre-season testing in Barcelona
Three McLaren personnel had to be treated at the medical centre at Spain's Circuit de Catalunya after a fire in the team's garage.
McLaren said the team members were "released shortly after" being admitted following what they said was "a small fire" that was "quickly extinguished".
The team said they were checking their car for damage.
They could not say if the incident will affect their involvement in next week's final pre-season test at the track.
McLaren and other teams were taking part in a private filming day at the track north of Barcelona.
The first pre-season test finished on Thursday, and the final one starts on 26 February.
