U.S. experts says that summertime colds are caused by different viruses than those that cause winter colds and can actually last much longer than the winter bugs.

The experts say that while winter colds are usually "nasty, brutish and short," summer colds tend to go on for weeks and can reoccur."

Summer colds are said to only hit about 25% as often as winter colds, but can often have more severe symptoms.

Experts say wintertime colds may occur more often because cold weather and lack of sunlight decrease the body's immunity.