All of a sudden a lot of loose talk about turning on the hot water in government buildings.

"Maybe Reagan can turn on the hot water for government employes," cry the spineless.

What this republic needs is less hot water and more cold showers, to begin with, and since turning off the hot water at the Bureau of Wee Bunnies is the only economy the Carter administration ever made, one would hate to see the policy overthrown by a bunch of extravagant Republicans flinging tax dollars around.

This may be the place to say, perhaps belatedly, but the opportunitiy never presented itself before, that Lyndon Johnson's habit of patrolling the White House for light bulbs left burning was one of that president's outstanding claims to love.

Let me make one thing clear, nobody wants to see absurd economies made in government. I for one would oppose renting the Rotunda of the Capitol to a hamburger chain, for example, even though money would be brought in thereby.

Such a thing would not suit the dignity of the capital city, so let us not start thinking of asinine projects of the sort.

Still, if only part of the Rotunda were used, and if instead of hamburgers they sold oysters and braised celery, if might be feasible.

There was a time we all would have raised hackles if the sacrosanct Mall were invaded by commercial ventures. But since the Smithsonian Institution evidently intends never to rest until the last Museum of Pickled Herring and Calliopes is eventually built on it, we might as well get a little revenue by selling lots to Lord & Taylor, assuming they would staff them with clerks who would actually accept your money for a tie.

As everyone knows, who reads those Proposed Schedule Changes on the city's bus system, late-night service will be abolished on some lines and other lines will discontinue service entirely, a loss of service that we should easily be abler to live with since fares will increase. The usual Metro logic.

One thing we could do is keep the subway system, which will be complete by the turn of the century, and drop the entire bus system. Some folk keep hinting -- if you read letters to the editor -- all we need is a new public transportation management, but I believe people say that in fits of anger.

If buses were abolished we could have mule carts.

In my own country, somewhat before I was born, we had a very good system of mule carts that went around the city to collect the dead, whenever we had yellow-fever epidemics, which was almost every year.

Do you think they ran on schedule? Hardly. But they ran, and everybody got on that was supposed to.

Once you stop pampering people, things begin to work out, haven't you noticed that's true?

When we lived on Western Avenue at Chevy Chase Circle the shower never worked. But in New Guinea during the war, all the homemade showers worked flawlessly. A good example of what I mean.

The mule carts, to get back to them, could start here and there at the edge of the town and wend their way, amid tinkling bells and perhaps some festive banners, toward the center of the city. We would hear them coming -- as we hear the man who sharpens knives or mends kitchen pots -- and run out in good time to board. The fare should be a dime. The mules could be kept at that fine stable in Rock Creek Park that's been closed and which is not, therefore, producing manure for city gardeners as it did.

Some would say we wouldn't save enough, with these projects, to justify the bother. But as President Kennedy used to say, let us make a beginning.

And certainly the hot water is real item; not many people know how outrageous a percentage of their fuel bill goes to produce hot water in their houses.

I think we need it, for dishes and the dogs -- I know old Luke flat refused to bathe if the water was not warm, though he was a sturdy hound -- and of course for human bathing. But these government workers, don't they have homes where they can get their hot water? I never use hot water here at this office, and indeed suggest we cut it off, why not?

It would be a shame if the Reagan administration, which promises a change of direction, should begin by changing the direction established by the Carter people in saving on hot water. What government workers did with all that hot water, nobody knows. Made pink tea, probably, with a taxpayer cut of $46 a pot.