Dave Hill from the Guardian read a blog post from an American tourist who was totally convinced that the "Stay Cool in the Heat" posters were all about Swine Flu.
She said about the bullet points, they "had nothing to do with the heat anyway. The bullets fed the hype and fear about swine flu (which the media there is freakin’ out about). It's important in advertising, as it is with slides, to make sure you’re communicating one clear message. The call-to-action to 'keep cool' might as well have said to wear surgical masks too."
It's amazing how things get mis-interpreted, although perhaps the guy wearing the mask read the "Stay Cool" posters that way as well.