Hmm.
Phil has a good point. I guess you ought to take better care of your instrument in future!
Here's a tip: when transporting your instrument from high to low humidity/temperature locations... if your instrument is stored in a hardcase, just loosen the clasps to allow the case cover to open a little bit. Give the guitar 10-15min to acclimatise to its surroundings before taking it out and then tuning it up.
When I go for a jam I know that the temperature difference between the inside of the case and the guitar itself would be "outside normal temperature" as compared to the cooler air-conditioned situation inside the studio. I will do the above measures not only to prevent humidity-related damage, but also to let the instrument and the strings adjust itself so that tuning won't be a crazy affair.