THE EMOTIONAL TEMPERATURE of the budget debate is rising. Speaker of the House O'Neill now vehemently promises a series of separate votes on some of the heart-wingers -- the programs for handicapped children, for example, and the money for school lunches. While Congress has voted limits on its spending totals, it has not yet changed the laws that actually control spending program by program.

That legislation is scheduled to come to the House floor later this month, and there has been some dissension within the Democratic leadership over tactics in handling it. The central question has been whether to do the whole hideous job quickly, in one up-or-down vote, or to require roll calls on each of the more sensitive and symbolic social benefits. That's now been resolved, apparently, in favor of the longer and more strenuous alterative.

"We don't think the educational program for the handicapped ought to be completely destroyed," Mr. O'Neill warmly declared a couple of days ago, when he was interviewd on "Issues and Answers." "We're going to give them a vote on it . . . We truly believe that America cares, that the man next door and the family next door cares for the fellow who has a handicapped child." He's probably right. There's a painful period of second thoughts ahead, as Americans take stock of the specific changes being swept along in the general enthusiasm for budget-cutting.

But if the House is going to retrieve some of the endangered programs, it also has a responsibility to raise the money to pay for them. Otherwise it is merely voting for bigger deficits, a course of action not calculated to improve the condition of either the Democratic Party or the national economy.

Mr. Reagan's assault on the budget has started a valuable and salutary process. You have to acknowledge that much, even if you don't like the cuts that Mr. Reagan wants to make, or the values that lie behind them. He is forcing Congress and the voters to take a hard look at the wide variety of outlays in the budget and to decide, one by one, whether they stay or go. There is no magic number of dollars to which the budget has to be held. But if this process works successfully, it will result in a budget of which each element is sufficiently strongly supported that -- for the first time in two decades -- there will be a political base for the taxes to balance it.

Mr. O'Neill is quite right to make the best possible case of the programs that, to his credit, he cherishes. But the test isn't simply whether they are popular. The test is whether the voters are ready to pay for them.