What type of smoke can be found on the floor and couch that could be harmful to babies, children and animals? first hand smoke
second hand smoke
third hand smoke
fourth hand smoke
Which one is it ? 1,2,3,4 ?

Thirdhand smoke is residual nicotine and other chemicals left on indoor surfaces by tobacco smoke. People are exposed to these chemicals by touching contaminated surfaces or breathing in the off-gassing from these surfaces. This residue is thought to react with common indoor pollutants to create a toxic mix including cancer causing compounds, posing a potential health hazard to nonsmokers — especially children.

They probably don't understand either 1. what the nightmare is about or 2. his anxiety and stress