I googled the image and then something surprised me. The white cross on a green background is the ISO (International Standards Organization) standard indicating first aid supplies! What? I took an informal poll of people within 20 feet of me, and only one person knew about this. He's a lifeguard trainer, so that made sense that he might have known this.
There are lessons to be learned here.
#1 -- Standards aren't always the same. We need to ask questions and notice details to be knowledgeable of our surroundings. First aid supplies just might come wrapped in an unexpectedly green package. Take 10 minutes in a new location (like a hotel, new office, or ball park) to familiarize yourself with your new surroundings, especially when you travel far from home. Identify the locations for critical areas like first aid supplies, exits, staircases, storm shelters, phones and the security office.
#2 -- People just don't always follow the standards. Expense, familiarity and convenience often lead people to ignore standardization. What may be obvious common sense to you may not be obvious or common. Don't assume that your needs (or potential needs) will be met by someone else. Ask and confirm that the resources you need will be there, or provide them yourself. You might be surprised at the number of small businesses that have no first aid supplies available at all. And a guest from Europe would be surprised to find my first aid kit in a red bag.