(CNN) -- Though no longer a hurricane, Sandy still brings the threat of flooding, snow and massive power outages to millions.
The deadly storm wreaked havoc as it made landfall Monday night, and many evacuees remain in temporary shelters. Even residents riding out the storm at home face significant damage and a tough cleanup in the days ahead.
Relief groups are already working to make sure everyone affected by the storm is cared for, and you can help.
Donate blood -- The Red Cross had to cancel about 300 blood drives because of the storm and supplies are running low. Visit RedCrossBlood.org or call 1-800-RED-CROSS to schedule a donation appointment in your area. The New York Blood Center is also collecting blood donations in the New York/New Jersey area.
Provide emergency supplies -- AmeriCares, Catholic Charities USA, Direct Relief International, Feeding America and Operation Blessing International are providing food, medical supplies, emergency kits and support for people in need.
Help outside the U.S. -- Hurricane Sandy took a deadly toll on the Caribbean before it hit the United States. Operation USA and the International Medical Corps are helping people affected by Sandy in Haiti and Cuba. Operation USA is also providing aid to the East Coast.
If you are planning to give to a nonprofit in the wake of any disaster, verify that it is legitimate. Charity evaluators like Guidestar and Charity Navigator are good ways to check that the organization you're donating to is established and your funds will go where you intend.