According to the passage, how does sweating cool the body?
Basic Understanding of a Variety of Texts · TELPAS Grades 8–9 reading. The correct answer, and the reasoning behind it.
Reporting category 2: find the main idea and key details, and follow what happens in stories and informational texts.
Read the passage. Then answer the questions.
Why Humid Heat Feels Worse
On a summer afternoon in Houston, the thermometer might read 94°F while the weather report says it "feels like" 108°F. In El Paso on a dry day, 94°F feels much closer to 94°F. The difference comes from water. Not the water you drink, but the water vapor in the air.
The human body cools itself mainly by sweating. Sweat is mostly water. When it evaporates from the skin, it changes from a liquid to a gas, and that change carries heat energy away from the body. This is also why a breeze feels so good on a hot day: moving air helps sweat evaporate faster.
How fast sweat evaporates depends on how much water vapor is already in the air. Humidity is a measure of that water vapor. When the air is dry, as it often is in West Texas, sweat evaporates quickly and the body cools well. When the air is humid, as it often is near the Gulf Coast, the air already holds so much water vapor that sweat evaporates slowly. It drips off or stays on the skin, and much less heat is carried away.
The National Weather Service combines air temperature and humidity into a single number called the heat index. The heat index is an estimate of how hot it feels to the human body in the shade. When the heat index is high, the body has a harder time cooling down, and the risk of heat exhaustion and heat stroke goes up.
Knowing the heat index can help people make safer choices. Coaches may move practice to early morning, and outdoor workers may take more breaks in the shade. On the most humid days, drinking water and resting out of the sun matter even more, because the body's usual cooling system is not working as well.
The question
Choose the best answer.
According to the passage, how does sweating cool the body?
- Sweat is colder than the air around it.
- Sweat blocks sunlight from reaching the skin.
- Sweat carries heat away as it evaporates.Correct answer
- Sweat reminds a person to drink more water.
Why “Sweat carries heat away as it evaporates.” is correct
This question checks understanding of a process explained in paragraph 2. The passage says that when sweat evaporates, the change from liquid to gas "carries heat energy away from the body." The wrong answers are common guesses that the passage does not support.
Why the other answers are wrong
- Sweat is colder than the air around it. — The passage does not say sweat is cold; the cooling comes from evaporation.
- Sweat blocks sunlight from reaching the skin. — The passage does not connect sweat to sunlight.
- Sweat reminds a person to drink more water. — Drinking water is mentioned at the end, but not as the way sweat cools.
Practice more of this
More reading practice for Grades 8–9, or see the TELPAS practice test for 8th and 9th grade.
This is an independent study resource. It is not affiliated with, endorsed by, or connected to the Texas Education Agency or the official TELPAS program. All questions here are original practice material written to match the published test design.