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Sweat Spot

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    The Exploratorium

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Sweat Spot

In this activity, learners use a chemical reaction to visualize where moisture forms on the body. Learners use the Minor's iodine-starch test, a diagnostic test that doctors use to detect hyperhidrosis (excessive sweating), to identify where moisture is forming. Learners also use this method to test the effectiveness of different antiperspirants.

Quick Guide

Preparation Time:
Under 5 minutes

Learning Time:
10 to 30 minutes

Estimated Materials Cost:
$10 - $20 per group of students

Age Range:
Ages 8 - 18

Resource Types:
Activity, Experiment/Lab Activity


Materials List (per group of students)

  • Iodine tincture (available at pharmacies)
  • Cornstarch
  • Variety of antiperspirants and deodorants
  • Magnifying glass or dissecting microscope
  • Paper and pencils/pens
  • Cotton swabs (optional)


  • Life Sciences
    • Human Body
      • Muscles and Skin
      • Medicine
  • Physical Sciences
    • Chemistry
      • Chemical Reactions
  • The Nature of Science
    • The Scientific Process
      • Conducting Investigations


To use this activity, learners need to:

  • see
  • see color
  • touch

Learning styles supported:

  • Involves hands-on or lab activities


This resource is part of:

Access Rights:

  • Free access


  • Yu, Julie


  • All Rights Reserved, Exploratorium, ©2007

Funding Sources:

  • National Science Foundation, 0610238
  • National Science Foundation, 0925383


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