A romantic Mexican vacation turned into a nightmare for The Hills stars Heidi Montag and Spencer Pratt when the actress fell ill.

The reality TV couple jetted off to Los Cabos at the beginning of the year (Jan08) to re-connect after calling off their nuptials at the end of 2007.

And while they were spotted having fun and holding hands on the beach, it was a very different story when they were back in their hotel room.

Montag told America’s Life & Style magazine, "I’ve been throwing up all night (on 9 January (08)."

Back in Los Angeles, The Hills star tells the publication, "I just got back from Mexico. I don’t know what I have; I don’t know if it’s food poisoning. I’m just so sick."