Keeping cool can make you sick. If you’ve ever felt a sniffle coming on in the summer months — particularly when you’re on vacation — then air conditioning could be to blame.

Berlin's Cool Factor: Hipster clubs, grimy graffiti and an honour payment metro By CHLOË WEBSTER Published: 13:30 EDT, 1 November 2013 | Updated: 12:05 EDT, 6 November 2013 ...