As the Christmas season is nearing, medical experts have cautioned against possible allergies one can contract from trees, triggered by allergens present in them.  J. Allen Meadows, former president of the American College of Allergy, Asthma & Immunology, pointed out how the trees often travel long distances to reach local markets, allowing mould to grow on it along the way. He suggested that one should air the tree outside before setting up to reduce the allergens in addition to spraying it with vinegar. Experts also suggested the use of masks while unpacking and setting up trees.