The man was shabbily dressed. Watching him approach, Phil Hansen figured he was probably homeless.

Hansen stood at the front of the American Red Cross office in Madison, Wis., where he was regional CEO at the time. He was moved by the sight of citizens streaming toward the building as they heard what had happened and came to help. It was Sept. 11, 2001.

The apparently homeless gentleman entered the office, pulled out a wallet and opened it. Inside was a single $1 bill.

“He said, ‘You need to take this for those people’ ” in New York, Hansen recalled. “And you could tell that he needed that one dollar. But in that moment, he needed it even more to help the people who were affected by this terrible event.”

In the wake of disasters, natural or otherwise, Americans can be counted on to step up and aid people who are suffering, said Hansen, who has worked with the Red Cross nearly 30 years and is now CEO for the Minnesota region. Hansen returned in October from Florida, where he worked in a fairgrounds shelter that housed more than 1,000 people, ranging from 4 days old to 100 years old.

The second half of 2017, unfortunately, has brought more reasons to help than usual. Hurricanes battered populations in rapid succession: Houston, Florida, Puerto Rico and the Caribbean. Massive wildfires blazed across Northern California. A catastrophic earthquake hit Mexico City.

Natural disasters in general have been rising in number and intensity in recent years, Red Cross officials said. This year’s mobilization of volunteers is the largest in the organization’s history.

It’s natural to want to reach out to fellow humans mourning deaths, recovering from injuries, sifting through rubble or struggling without power or drinking water.

But, officials caution, some kinds of help are more helpful than others.

Cash is king

Like a kindly aunt wanting to give a nephew a present to unwrap instead of an impersonal gift card or check, people donating after disasters often want to give something more tangible than money.

“Cash is the best, most caring gift you can provide to individuals who are recovering from a disaster,” said Kris Kewitsch, executive director of the St. Paul-based Charities Review Council. “People giving items, with the best of intentions, becomes its own crisis.”

Donations from businesses — sunscreen, diapers, bottled water, shovels, cleaning supplies and so on — are welcome. Anybody with a quantity of new and potentially useful items can contact the Red Cross or other charitable organizations to see if there’s a need.

But random items donated by individuals, such as secondhand clothing, generally aren’t useful. They take up storage space. They pull volunteers away from helping people one-on-one in order to sift through piles, sorting and cleaning items.

“Years ago I had a job in Florida where people sent winter coats, roller skates — a variety of very inappropriate things,” Hansen said. The Red Cross works to pass those items along to agencies that can use them, because “people are reacting from their heart.” But piles of old clothes have been known to decay before anyone could deal with them.

Cash can be used to buy whatever supplies are most urgently needed. Purchases from local stores can help devastated economies start to recover.

Cash donors should make sure they’re contributing to a reliable organization, Kewitsch said. “Buyer beware. If you’re donating to a Go Fund Me request, do some research on that individual or organization so you can be sure they can be trusted.”

Donors should also remember that the suffering doesn’t end when the disaster leaves the headlines. With one hurricane on the heels of another, it may be easy to lose sight of earlier crises. Two months after Hurricane Harvey struck, hundreds of Houston residents were still living in shelters, Hansen said. And rebuilding demolished communities takes far longer. Red Cross volunteers are scheduled for deployment through the holidays.

“There’ll be a very long recovery process,” Hansen said. “I wouldn’t be surprised if it’s years.”

Blood, sweat and tears

There are other ways to help besides donating money.

“We’re the only organization that asks you for your time, your money and your blood,” Hansen said. But two of the three take some advance preparation.

The massive blood supplies that are sent immediately to disaster areas are collected before the disaster strikes. Freshly drawn blood takes a few days to process, so donations are welcome throughout the year.

Only 38 percent of the population is eligible to give blood (you can be disqualified for anything from medical conditions to having traveled to countries with diseases). And among those eligible, only 8 percent actually donate, Hansen said.

Those who want to contribute time and labor to disaster sites may have to wait for the next catastrophe. The Red Cross trains its volunteers, then generally has them practice with smaller disasters close to home, such as house fires. Some volunteers focus on local disasters indefinitely. This year, Red Cross volunteers responded to about 600 events in Minnesota, Hansen said. They often arrive while the fire department is still dousing flames to help families plan for recovery.

Trained Red Cross volunteers who travel to an event like a hurricane commit to spending at least a couple of weeks. They jump on planes not knowing exactly what they’ll be assigned to do until they get there. In October, about 180 Minnesotans were deployed to other states. The work can be hard — 12- to 14-hour days, nights sleeping on cots, sweltering in buildings without power or air conditioning.

“There are some pretty courageous folks that are volunteering to do this work,” Hansen said. “It’s a great way for the American citizenry to support their country.”

Those whose physical limitations prevent them from roughing it can still help, doing assignments that match their abilities.

Another way to help is by preparing your own family for a disaster, said Carrie Carlson-Guest, regional communications officer for the American Red Cross Minnesota. “The people that can take care of themselves and their families, and have a plan in place, let first responders help people who can’t help themselves.”

The emotional rewards of disaster response are immense, Hansen said. “It’s a huge privilege, actually, to be with someone in that moment where they’ve lost almost everything, and to be with them and give something back.”

But it’s emotionally draining, as well. After Sept. 11, Hansen remembered, “It was two weeks of just intensity before I finally sat down and, I’ll be honest, I sat there and bawled on the couch for an hour.”