A Brooklyn gas-station attendant working in the bitter cold Saturday suffered an apparent seizure while filling up a tank — but instead of helping him, the car’s occupants jumped out and robbed him as he lay on the ground, cops said Tuesday.

The worker at the Allegiance gas station on 86th Street in Gravesend was filling up the tank of a white Infiniti SUV around 10:30 p.m. when the incident occurred, police said.

The 39-year-old attendant suddenly collapsed to the ground and began shaking uncontrollably, cops said.

But instead of helping the suffering man, the SUV’s driver and two other men in the car hopped out and snagged $140 in cash from his hand and rifled through his pockets for his wallet before hopping back in the car and speeding off with both, police said.

The victim, who suffers from a pre-existing medical condition, refused treatment at the scene, cops said.