Quick answer

Choose the fleece Flying Squirrel pajama for cold winter nights and the lightweight version for warmer rooms or year-round use in temperate climates.

Why fabric weight matters for safe sleep

A baby's sleep sack should keep them comfortable without overheating. The American Academy of Pediatrics (AAP) recommends a safe sleep environment that avoids loose bedding and helps maintain a consistent temperature. Both Flying Squirrel pajama options are designed with these guidelines in mind, but the fabric weight changes how they perform in different room temperatures.

Key differences between fleece and lightweight

The fleece version (Sleeping Baby Perfect Penguin Flying Squirrel Pajama - Fleece) uses 100% polyester fleece, which traps heat effectively. It's ideal for cooler months or air-conditioned nurseries. The lightweight version (Sleeping Baby Girl Nautical Flying Squirrel Pajama - Lightweight) uses a thinner polyester fabric with a lower TOG rating, making it breathable for warmer conditions. Both share the same wearable blanket design with ribbed cuffs and a loose fit, but the fabric choice directly impacts your baby's thermal comfort.

Fleece vs. Lightweight: Trade-offs

  • Warmth level: Fleece provides higher insulation for cold rooms (below 68°F / 20°C). Lightweight is better for rooms 68-72°F (20-22°C) or warmer.
  • Breathability: Lightweight fabric allows more airflow, reducing the risk of overheating. Fleece is less breathable but still meets safe sleep recommendations.
  • Year-round use: Lightweight works well in most seasons if your home stays warm. Fleece is best reserved for cold months unless you keep the nursery cool. Check your nursery temperature before deciding. If you're unsure, the lightweight version is more versatile.

Product facts at a glance

Which fabric is right for your baby?

Best for

  • Cold winter nights or air-conditioned rooms where extra warmth is needed
  • Parents who want a cozy, snuggly sleep sack for cooler months

Not for

  • Warm climates or heated nurseries where overheating is a concern
  • Babies who tend to sleep hot or sweat easily