This Subway worker had a chance to “ketchup” on some alone time.

Karlee Daubeney channeled her inner MacGyver after she accidentally locked herself inside a shop refrigerator, cleverly using tomato sauce to send a “help me” message to co-workers.

“At first I was in a state of panic and I was looking for anything that could have opened the door,” Daubeney, 20, told the Gloucester Citizen. “I was obviously on shift alone which was scary enough as the windows had been kicked in a few weeks before and I didn’t feel comfortable being there.”

But a jug of ketchup offered a glimmer of hope.

“I was trying to write ‘help’ on pieces of cardboard to slide under the door,” she explained. “It got to the stage I was so cold I didn’t have the energy to bang on the door and I only had leggings and a Subway top on.”

But instead of being seen by CCTV operators like she had hoped, Daubeney’s make-shift message went unseen until 7:30 a.m. the next morning — when a colleague returned to work for her shift.

“My muscles became so cold I found it really hard to walk for a few days,” she said, describing her condition. “I had migraines and dry skin around my nose. When I went to hospital the next day I was told I was close to having hypothermia and I made myself as warm as I could when I got home.”

Daubeney has taken her franchisee to court over the incident, which took place last December.

She has accused them of breaching workplace health and safety laws by not ensuring the welfare of its employees, the Gloucester Citizen reports.

Daubeney also says she’s still scarred from the ordeal — and even becomes nervous whenever a door is shut behind her.

“I didn’t leave the house for a long time afterwards as I was suffering from really bad panic attacks — it has been nearly a year and I still suffer from anxiety,” she said.