This is why you should listen to Quirks & Quarks because you can learn the answers to riveting scientific queries of the day, like this one. 

The sensation of mint as cold has long fascinated me, but I have never known why mint makes my mouth chilly. Now the answer is here. Apparently mint, like Tabasco sauce, stimulates your taste buds with a sensation like pain. It’s not technically a taste, but rather a feeling of pain! 

Because your taste buds have been primed by this painful mint, anything cold that you eat afterward with seem colder. Interestingly enough, anything hot that you eat afterward will seem hotter. 

Mint also increases your salivation and washes away thick protective saliva from your taste buds, so more of the cold or hot thing hits your naked, shivering taste buds.