---
title: "What Is Heat Rash? Heat Stress and Hydration Glossary"
description: "Heat rash is a skin irritation from heavy sweating in hot, humid weather. It shows as red clusters of pimples or small blisters, often on the neck, chest and..."
url: https://jmarsolutions.multisites.ai/glossary/heat-rash
publisher: JMAR Solutions
phone: +1-214-632-7780
quote: https://jmarsolutions.multisites.ai/contact
---

Heat illness

# Heat rash

Heat rash is a skin irritation from heavy sweating in hot, humid weather. It shows as red clusters of pimples or small blisters, often on the neck, chest and elbow creases.

Heat rash is a skin irritation caused by heavy sweating in hot, humid weather. It looks like red clusters of pimples or small blisters. It usually appears on the neck, upper chest, groin, under the breasts and in elbow creases.

NIOSH says workers with heat rash should move to a cooler, less humid place if possible and keep the area dry. Powder can add comfort. Do not use ointments or creams. Heat rash is a sign that the body is under [heat stress](https://jmarsolutions.multisites.ai/glossary/heat-stress), so check the crew's shade, breaks and water. Long sweaty shifts in thick gear raise the risk, so plan [work/rest schedules](https://jmarsolutions.multisites.ai/glossary/work-rest-schedule) that let skin dry.

[From JMAR SolutionsHydration programs and toolbox talks for crews](https://jmarsolutions.multisites.ai/hydration-programs)

## Related terms

-   [Heat stress](https://jmarsolutions.multisites.ai/glossary/heat-stress)
-   [Heat cramps](https://jmarsolutions.multisites.ai/glossary/heat-cramps)
-   [Work/rest schedule](https://jmarsolutions.multisites.ai/glossary/work-rest-schedule)
-   [Heat exhaustion](https://jmarsolutions.multisites.ai/glossary/heat-exhaustion)

## Sources

1.  [CDC NIOSH: Heat-related Illnesses](https://www.cdc.gov/niosh/heat-stress/about/illnesses.html)
2.  [CDC NIOSH: Heat-related Illnesses](https://www.cdc.gov/niosh/heat-stress/about/illnesses.html)

![Ironworkers silhouetted on a steel frame against a hot orange sunset](https://jmarsolutions.multisites.ai/_astro/sunset-steel.IhAMDca0_6wk53.webp)

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