Seventeen people were taken to hospital in a suspected carbon monoxide poisoning incident at a food-processing plant in Cornwall.
People working in the vegetable packing area at Riviera Produce at Connor Downs began to complain of "feeling unwell" at about noon.
Two ambulance staff were among the casualties.
A fleet of ambulances took the casualties to the Royal Cornwall Hospital in Truro.
Their condition was not thought to be life-threatening.
Vomiting and confusion
The company said the poisoning might be linked to a forklift truck at the plant.
Managing director David Simmons said tests were being carried out on the truck but the cause was not yet known.
Inhaling carbon monoxide, which is colourless and odourless, reduces the blood's ability to carry oxygen and can be fatal.
Symptoms include headache, nausea, dizziness, vomiting and confusion.
Firefighters wearing breathing apparatus used a gas detector at the plant, which has been evacuated.
About 40 people are normally employed at Riviera Produce, which prepares and packs cabbages and cauliflowers for supermarkets across the country.