Question

we cannot always rely upon our senses of touch '.

Answer 1

this is true. it can be explained with a activity.
take three buckets. put hot water in bucket 1 and like warm in bucket 2. and cold in bucket three.
now put one hand in bucket 1 and other in bucket 3 . after some time put both hands in bucket 2. you will see that the hands put in bucket 1 will experience coldness. and the hand earlier put in bucket three will experience hotness.
thus w can't rely on our sense of touch