why is the stem of the thermometer made up of thick glass? Share with your friends Share 0 Vikas answered this Answer The stem of the thermometre made up of thick glass because of following reasons given as 1 To contain the mercury and to withstand high temperatures being measured.2 For holding mercury which is poisonous as well as to give a magnifying effect while reading. 1 View Full Answer Shaurya Verma answered this maybe because the mercury iside the thermometer is poisonous and doesn't damage a patient 1