18. Tight clothing
We’ve all been told that exercise will help keep you healthy, but did you know that sitting still could actually prove lethal? Well, on long-haul flights it may do, as they triple the risk of deep vein thrombosis (DVT) – a condition that could have life-threatening consequences. And wearing tight clothing can make the chance of DVT even greater. So, dress in looser items, if possible, when traveling for hours on end.