Many executives say their businesses have been adversely affected by uncertainty over the fiscal cliff, and Caterpillar is no different.

"I talk every day to our customers around this country, and they're all scared to death of what happens in January," Doug Oberhelman, the company’s CEO, tells CNBC. “All I know is that going over the cliff is too hot to handle."

The fiscal cliff refers to $607 billion of automatic spending cuts and tax increases that will begin Jan. 1 if Congress and the White House don’t reach a budget agreement before then.

Editor's Note: 'It’s Curtains for the US' — Hear Unapologetic Warning from Prophetic Economist.

"I don't think we should risk it at all," Oberhelman says. "But if we do go over the cliff, the downside is a lot more prevalent to where we are today — and lots of things will happen."

One of them is a recession, economists say.

“If you take between 3 percent and 4 percent of total spending out of an economy, a recession is very likely to follow,” Alan Blinder, former vice chairman of the Federal Reserve, writes in The Wall Street Journal.

Entitlement reform and a debt ceiling increase should be part of any fiscal cliff deal, Mark Zandi, Moody's Analytics chief economist, told Congress, CBS News reports.

"I don't think you can break this apart," Zandi said.

Editor's Note: 'It’s Curtains for the US' — Hear Unapologetic Warning from Prophetic Economist.