In PS, How did Quirell shake hands with HP without burning?

[Vanessa]

No: HPFGUIDX 28927

--- In HPforGrownups at y..., kidzero7 at y... wrote:
> Sorry if this has been covered... (I tried a search first)
> 
> In PS, Prof Quirell shakes hands with Harry Potter while he's 
> visiting Daigon Alley. How is this possible when touching Harry 
> should 'burn' him? (I have some theories, but I'll hold on to them 
> for now.)
> 
> thanks!

Voldemort did not 'enter' Quirrell untill after he had botched the 
Gringotts Break in, later that same day.  There was no reason prior 
to this why Quirrell couldn't touch Harry just like anyone else.