What does that mean? The enemy tables don't go lower than 1?
It can be handled in three ways, depending on preference:
You may simply treat it as a Heat level of 1 and roll up your opposition as you normally would.
This is the typical option for a wargames campaign.
After all, we're here to have a shoot-out right?
You can opt to use it as a "light" encounter, facing a number of Goons equal to your Group Size minus 2.
These Goons will have no upgrades or additional gear of any kind.
This can feel like a waste of time for a hardened player party, but can be a good introduction for a new player or a very small group of characters on their first encounter.
You may treat it as a "quiet job".
Set up a suitable scene and make a few rolls on the tables in the "Casual Encounters" chapter (page 69).
Sometimes something will happen, sometimes it will not.
This option works well for more role-play oriented players and the odd amateur-writer.
In a Game Mastered campaign, you may wish to use this as an excuse for a role playing encounter.
Maybe you meet an old friend or a nemesis shows up to twirl their moustache for a bit.