high altitude caramel
I live at about 5800 feet about sea level. I find that when making caramel or fudge, I have to lower the temperature to which I cook it about 10 degrees. The rule is one degree for every 500 feet above sea level. When I make caramel sauce, I heat the cream to a simmer and add it to the caramelized sugar. It seems to work better than using cold cream.
Chewy caramels, however, need to reach 257-260 degrees in order to set up properly. I tried making a batch using the lower temperature and they never set up.
Hope this helped.