Good afternoon. At some point, my characters had a low HP level. For example: Acher Zenon III of the fourth level has 9/9 HP. but if I go to Temple and heal, the HP rises to the normal value of 38/9 HP. Please tell me how to increase the minimum HP level.

After I bought food and rested, the HP level returned to normal.
The issue is resolved, the topic can be closed.

The problem was that your characters were poisoned.

When you are poisoned in MM1 and 2, every time you rest you lose half of your max HP. So a poisoned character with 32 HP would rest and wake up with 16/16. Rest again and it would be 8/8, then 4/4....

It does not go away on its on, but can be removed by the 4th level Priest spell Cure Poison, or any temple for a fee.