What reading level is Body Warriors: The Immune System (Raintree Fusion: Life Science)?

Body Warriors: The Immune System (Raintree Fusion: Life Science) by Lisa Trumbauer is at a Level 3-4 reading level. Recommended for Middle Grades readers (Ages 9-12).

Does Body Warriors: The Immune System (Raintree Fusion: Life Science) have any content warnings?

Body Warriors: The Immune System (Raintree Fusion: Life Science) has a HootRating of 8C (Clear). No specific content flags noted. On HootRated, every book is rated across four dimensions — emotional, physical, social, and thematic — to help parents make informed choices.

How many pages is Body Warriors: The Immune System (Raintree Fusion: Life Science)?

Body Warriors: The Immune System (Raintree Fusion: Life Science) by Lisa Trumbauer is 32 pages (approximately 1,729 words).

Reviewed by HootRated editorial · Last updated May 18, 2026

Body Warriors: The Immune System (Raintree Fusion: Life Science)

Lisa Trumbauer

Body Warriors: The Immune System (Raintree Fusion: Life Science)

Age Rating, Reading Level & Content Guide

The Immune System

by Lisa Trumbauer

Raintree Fusion; Raintree Fusion: Life Science

Reading Level 3-4 8C Ages 9-12 Balanced Read Page-Turner

The text is written at a 3rd grade reading level, the subject matter is intended for middle graders (ages 9–12), and the content is gentle with no concerning themes.

Buy on Amazon Listen on Audible

We may earn a commission from these links. Bookshop.org supports independent bookstores with every purchase.

About This Book

Discover the incredible defenders inside your body working tirelessly to protect you from germs and keep you strong. Meet the tiny heroes of your immune system and learn how they fight off invaders to keep you healthy every day. This exciting journey reveals the amazing science behind your body's natural protection.

Themes

Science & NatureAnatomy & PhysiologyEducationHealth

Quick Assessment

This is a Level 3-4 book with gentle content intensity. No notable content concerns flagged. Written for readers ages 9-12.

Why we rated Body Warriors: The Immune System (Raintree Fusion: Life Science) 8C

Body Warriors: The Immune System (Raintree Fusion: Life Science) is written at a Level 3-4 reading level across 32 pages (approximately 1,729 words). Strong independent readers around grade 4.7 can typically handle this book on their own; with parent or teacher support, Body Warriors: The Immune System (Raintree Fusion: Life Science) works for readers up to grade 5.7.

Read aloud, Body Warriors: The Immune System (Raintree Fusion: Life Science) takes about 12 minutes, which fits within a single read-aloud session.

We rate Body Warriors: The Immune System (Raintree Fusion: Life Science) as 8C ("Clear") because the content sits in the "Gentle" range — no conflict beyond everyday childhood experiences. Across our four dimensions (emotional, physical, social, thematic) the book reads as evenly gentle; no single dimension stands out as a concern.

No specific content flags were raised by community reviewers, which is consistent with the gentle intensity score.

Thematically, Body Warriors: The Immune System (Raintree Fusion: Life Science) explores science & nature, anatomy & physiology, education, and health — these threads give the book room to mean different things to different readers.

Good fit for

✓ Children in the Ages 9-12 range — the maturity and attention span match the story's pacing.
✓ Reluctant readers who need fast-paced, hook-heavy stories to stay engaged.
✓ Kids drawn to stories about science & nature, anatomy & physiology, education.
✓ Readers who fall hard for one book and want a long series to live in — there is one more book in the Raintree Fusion; Raintree Fusion: Life Science series.
✓ Curious kids who prefer real-world topics over made-up stories.