A man wearing an inflatable sumo wrestler suit knocked himself out after bouncing off a work colleague during horseplay.
The 40-year-old, from Southampton, had been at an event in Gloucestershire with workmates when the accident happened at 6pm yesterday, West Midlands Ambulance Service said
Medics said the man had donned the blow-up sumo suit at Kemerton Park, near Tewkesbury.
An ambulance service spokesman said: "On arrival, ambulance staff were told the man had launched himself at a colleague, but when he bounced off he fell backwards and landed on his back and head.
"The man was knocked unconscious for a short period before coming round but he was not fully alert.
"He was complaining of pain in his nose, left shoulder and left leg."
He was immobilised and airlifted to Gloucestershire Royal Hospital for further assessment and treatment.