President Reagan asked the public yesterday to help him make Democratic congressmen "feel the heat" and defeat Democratic budget proposals that would increase social program spending and halve the 10 percent increase sought for defense spending.

In his weekly Saturday radio address, Reagan said he will not be "stampeded" by the Democrats' budget victory in the House last week but he added that protecting his economic policies is not his battle alone.

"I intend to do everything I can to protect this recovery all of us have worked so hard to achieve," he said. "But this isn't just my struggle. It's yours, too. You're not just spectators and I need your help. Together we still have time to beat back the unfair tax increases, hold the line on spending, and keep America strong.

"If you can't make the big spenders see the light, you can make them feel the heat. Please tell your representatives not to turn back the clock and squander America's future."

Reagan's remarks contrasted with his comments during a brief White House news conference Friday when he complimented Democrats for bipartisan cooperation on Social Security and emergency jobs legislation.

In the Democratic response to the president yesterday, Sen. Jim Sasser (D-Tenn.) pointed out that even some members of Reagan's party are "unwilling to support his budget."

Sasser criticized Reagan for finding it acceptable to increase the size of the deficit by "raising defense spending to the largest level in history," while offering "big tax giveaways to the wealthy."

"This is typicial," Sasser said, "of the misplaced priorities of this administration. Priorities that favor the wealthy and the special interests, but ignore the 11 million Americans who still can't find jobs. And they ignore the thousands of businesses which are going bankrupt each month."