Final answer:
Workers must use a flameless electrical heat gun set below 1100 degrees Fahrenheit when removing lead-based paints to prevent lead poisoning.
Step-by-step explanation:
When removing lead-based paints in residential housing units, it is essential to use a flameless electrical heat gun type softener. The temperature of the heat gun must be set below 1100 degrees Fahrenheit to avoid creating lead fumes, which are hazardous if inhaled. Overheating lead can release harmful lead vapors into the air, which contributes to lead poisoning. It is important for worker safety to maintain appropriate temperatures during the paint removal process.