TEL AVIV, JAN. 19 -- One Jerusalem pet-owner doses his dog with tranquilizers and wraps its snout with a wet towel saturated with baking soda, but he has discovered that it is no mean feat to keep the canine "gas mask" in place throughout the nightly emergency alerts.

Mothers put their babies into makeshift tents made of plastic sheeting, but find that the terrified screams the infants emit when they see adults in grotesque rubber masks are more disconcerting than the wailing air raid sirens.

In the sweltering heat of a beachside hotel's crowded gas-proof shelter, an elderly visitor from Haifa waddles around in heavy arctic boots and a rubber suit, trying to focus his camera through his protective goggles as he takes pictures of his friends.

This is life in the sealed rooms, or hader atum -- words that almost overnight have become a common expression in the constantly expanding vocabulary of modern Hebrew.

During the tense buildup to Thursday's launching by U.S.-led forces of Operation Desert Storm against Iraq, Israelis feverishly constructed crude, gas-resistant shelters in their homes, following the instructions of civil defense authorities in anticipation of the launching of chemical weapons by Iraq in an effort to draw Israel into the war and weaken the coalition arrayed against it.

The Israeli civilians sealed the windows and doors of their most expendable rooms with plastic sheets and tape, provisioned them with canned food and water and then waited for the war that everyone hoped wouldn't come.

Now they are using them, and are discovering that the sealed rooms are even more oppressive and claustrophobic than the underground bomb shelters that have been familiar to Israelis since the Jewish state was founded 43 years ago.

So far, Israelis have had to flee to their gas shelters during two Iraqi missile attacks and five false air-raid alerts, the most recent being sounded tonight in Tel Aviv and Jerusalem.

"It's living like a mole," one south Tel Aviv man said a few hours after the first Iraqi Scud missiles fell on this sprawling Mediterranean city at 2 a.m. Friday. The claustrophobic feeling, he said, is magnified by the tight-fitting rubber gas masks issued by the Israeli Defense Force and which seem to make breathing a labor and talking almost impossible.

But despite the nightly hardships and the growing anxiety that chemical weapons are designed to instill among civilians, many besieged Tel Aviv residents have maintained equanimity through the ordeal.

Guests on a popular television talk show walk onto the sound stage, gas masks swinging at their sides; Tel Aviv Mayor Shlomo Lahad jokes that the Iraqi missiles have found the only empty parking places in his city; one survivor of a missile attack today in a north Tel Aviv neighborhood decided to name her new dog after Iraqi President Saddam Hussein.

"We're taking him with us," the woman said as she was evacuated from her damaged home and moved to a hotel. "We named him Saddam, even though he's a good dog."

However, beneath the comic relief, debate is emerging over whether civil defense authorities made the right decision when they decided to instruct all Israelis to retreat to above-ground, gas-resistant rooms in their own homes instead of to the heavily fortified underground bomb shelters located throughout residential neighborhoods.

The debate has emerged because all of the Iraqi missiles launched against Israel so far have carried conventional high-explosive warheads, suggesting the possibility that Iraq is not yet capable of delivering gas or chemical warheads on their Scud missiles.

Critics of the civil defense policy suggest that even though there have been no deaths or even serious injuries caused directly by exploding missiles, the above-ground sealed rooms would provide little protection against a near or direct hit by one of the conventional warheads.

In contrast, the concrete bomb shelters are designed to take even a direct hit without injury to the occupants. But a missile that hit a community center in today's barrage landed squarely on an unoccupied bomb shelter, damaging it heavily.

Conceding that legitimate questions about the choice of shelters have been raised, Brig. Gen. Nachman Shai, chief spokesman of the Israeli Defense Force, today said he believes the sealed rooms still represent "the best way, after long analysis, that we can give the best protection to the people." Because poison gases tend to settle, underground shelters are thought to be more vulnerable to a chemical attack, analysts have said.