Can you really get sick after you've just been physically active and step out in to the cold?

Why does this happen?

Medical science does not really know half of what it professes to know. Most of the old-wives tales science is proving to be true. A human being who is not accustomed to living in cold weather is extremely vulnerable to cold temperatures for the simple reason that this shock to the system impairs the immune response. Source(s): Clinical laboratorian.

No...it's an old wives tale. You get sick from bacteria and viruses.

I'm a nurse.
No. The only physical ailment that you can get strictly for cold temperature is frostbite/hypothermia. The old wisetale is being out in the cold or out in the rain is plain rubbish. The only thing that can happen to you, even if you just ran 10 miles on a treatmill and then stepped outside in 50 degree weather, is a possible headache and perhaps some slight discomfort breathing. That's mostly because you've been exercising and your lungs are used to air at a certain temperature, and oftentimes the change in temperature, if drastic enough, can make breathing slightly uncomfortable.

But no, you can not get the flu or anything like that from cold or wet weather. It takes actual germs to cause that.
Do I believe this? Not for a moment. My boyfriend is a paramedic/firefighter, and one time I asked his boss why people got sick from being out in the cold. This was the answer he gave me (from an answer their medical advisor gave them) - colds are more prevalent in the winter, but not necessarily because of the cold - it's because people tend to stay inside more during the winter, and in doing so, it causes the germs to be spread around in a confined space, such as a house or a business. So, the answer is this - No, you can't get a cold from being in the cold. That's just an old wives tale.
no, that's an old wives' tale. colds come from germs. of course if your in the cold with someone who has a cold and you hold hands...............
reading medical columns on net, and from several other sources I really can't remember. just ask a dr. he'll tell you the same about colds. also "echinacea" should hike up your immune system so you don't get any in the first place. works for me!