You are given two cup of coffees. You can determine which one is hotter just by touching it. But is sense of touch reliable measure of hotness and coldness?
Sometimes Reliable
Hotness or coldness is a relative term so in many cases just by a sense of touch you can't determine which is hotter. Suppose you are given two cans, which are red hot, so in such situations you can't even touch the cans, determining its level of hotness is far away. That's why sense of touch is not always useful.