Roanoke Co., Va. -

Millions of people are doing it- tossing buckets of ice water over their heads and challenging friends to do the same.

It's called the Ice Bucket challenge and it's spreading fast on social media while also raising millions to fight Amyotrpic Lateral Scleroris (ALS) which is often referred to as Lou Gehrig's Disease.

Here's how it works:  A person posts a video dumping a bucket of ice water over his or her head and then challenges three other friends to do the same within 24 hours or make a $100.00 donation to the ALS Association.

Some call it social media peer pressure.

"If you don't rise to the challenge. If you don't do the ice bucket dump then somehow you're not a good person," said Dr. Lyn Day, a psychologist with Tanglewood Counseling in Roanoke County.  "I  don't think anybody intends to send that message but I think that's the message we receive which is a bit unfortunate."

Day encouraged people to have fun with the challenge if they want to, but not to feel pressure to do anything they don't want to do.

"Who made those rules and why do we feel like we have to follow those rules?" Day said. "That's the message I'd like to give as a psychologist. These are arbitrary rules that you don't have to follow.  Do what feels right for you."

Day said people should make a donation because it comes from the heart, not because they feel peer pressure.  She said the pressure people feel on social media is sometimes great.

"It's a whole different level of peer pressure. Some peer pressure is good but most peer pressure we hope to outgrow and think independently," Dr. Day said.

"I'm not saying it's a bad cause.  It's wonderful to raise awareness. It's wonderful they are raising money.  I just want people to keep perspective," said Dr. Day.

The ice bucket challenge began as a way to raise money for different organizations, but it was a man with ALS from Boston who started asking that the challenge donations be made for the ALS Association. 

ALS is a progressive neurodegenerative disease that affects nerve cells in the brain. There is no cure.

In just three weeks, since July 29th, the ice bucket challenge has raised $13 million  for the national ALS organization, and the regional district which covers Virginia, Maryland and Delaware tells WDBJ7 donations have tripled in the past few weeks.