Why do some objects feel colder when in reality they are the same temperature?

In this video pedestrians pedestrians in a park are asked why a hard drive
and a book sitting at the same temperature have a different temperature  feel to it.  The hard drive feels colder than the book.  He then takes an   aluminum plate and a plastic plate to see which plate melts ice quicker.  Even though the aluminum plate feels colder, it melts the ice quicker.  This is a good experiment to try with your students.