Heavy Air Reading Passage
Applied Science & Health Literacy
Lexile®: 300L Accessible High School Reader
Heavy Air: The Science of Humidity
Why Water in the Air Traps Heat and Changes Practice
Name:
Date:
Directions: Read the text below. Look at how moisture in the air changes how sweat cools your body. 256 Words
It is a hot summer day. You walk outside. The air feels sticky. It feels very thick. Your shirt sticks to your skin right away. You check your phone. It says eighty-five degrees. But it feels like one hundred degrees. Why does it feel so hot? The answer is humidity. Humidity is water in the air. The water is a gas. You cannot see it. But the water is all around you.
Warm air is like a sponge. It can hold a lot of water. Cold air holds less water. Weather news talks about relative humidity. This number tells how full the air is. Think of a wet sponge. When relative humidity is one hundred percent, the air is full. The air cannot hold more water. Then we get thick fog. Or we get rain.
You run or play sports. Your body gets hot inside. Your brain tells your skin to sweat. Sweat is water on your skin. On dry days, sweat dries fast. The water turns into gas. When sweat dries, it takes heat away. This process is called evaporation. It cools down your skin. Sweating keeps you safe in the heat.
Humid air is different. Humid air is already full of water. It has no room for your sweat. So your sweat cannot dry. It just drips down your face. It soaks your clothes. Your body traps its heat. You get hotter and hotter. High school coaches watch the heat index. The heat index uses temperature and humidity. It shows how hot the air really feels. If it is too dangerous, practice moves inside.
How Humid Air Traps Heat (3 Simple Steps)
Body Reaction Chart
1 Body Gets Hot
Hard workouts make you hot inside. Your body makes sweat.
Inside Heat Rises
2 Sweat Dries (Dry Air)
Sweat turns to gas. It dries up and takes body heat with it.
Body Cools Off
3 Sweat Fails (Humid Air)
Full air rejects sweat. Sweat drips. Heat stays stuck inside.
Danger: Too Hot
Heat Index Rule: Air Temp: 88°F + Humidity: 75% → Feels Like: 103°F (Danger!) Move Practice Indoors
High School Earth Science & Health (300L) Turn to Page 2 for Questions → Page 1 of 2
Reading Questions & Evidence
Part A: 5 Literal Questions Part B: 5 Inferential Questions
Comprehension Questions
Answer each question with a complete sentence using facts from the text.
Total Score: ______ / 10 pts
A Literal Questions
Find in the Text
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According to the text, what is humidity?
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What does it mean when relative humidity is 100%?
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What happens to body heat when sweat dries into the air?
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Why can't sweat dry on a very humid day?
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What two things are used to find the heat index?
B Inferential Questions
Think & Figure Out
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Why does an athlete feel cooler in dry air than in humid air at 90°F?
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Based on paragraph 2, why does morning fog form when humidity hits 100%?
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If an athlete's shirt is soaked with dripping sweat, are they cool? Why or why not?
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Why might a coach move practice inside even if the air is only 84°F?
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If the night gets cold but moisture stays the same, does humidity go up or down?
Strategy Tip: Literal answers are right in the text. Inferential answers require thinking about why things happen.
Literal: ___/5 | Inferential: ___/5
High School Earth Science & Health (300L) Heavy Air: Reading Comprehension Assessment Page 2 of 2
