The Emergency Survival Bag & Whistle is a compact, race-compliant survival bag designed for trail runners, ultramarathoners, and fastpackers who need reliable emergency protection without adding bulk. At just 129g, it’s one of the lightest and most packable bivvy bags on the UK market — and it’s priced to be accessible for every runner, not just elite athletes.
Whether you’re tackling a solo fell run in unpredictable weather or preparing for a mandatory kit check at your next ultra, the Harrier bivvy bag offers peace of mind, visibility, and warmth in a minimalist package.
Specifications Overview
| Feature | Detail |
|---|---|
| Packed Size | 10 x 7 x 7 cm |
| Unfolded Size | 210 x 90 cm |
| Weight | 129g |
| Material (Bag) | Polythene |
| Material (Outer Case) | DWR-treated ripstop polyester |
| Waterproof Rating | Water-resistant outer case; polythene bag is sealed |
| Visibility | Bright orange colour for rescue spotting |
| Included Accessories | Whistle, printed emergency instructions |
| Price (RRP) | £11.99 |
Design and Build Quality
The Harrier bivvy bag is built with trail practicality in mind:
- Polythene survival bag: Tear-resistant and windproof, designed to retain body heat and shield against cold ground
- Ripstop polyester case: DWR-treated for water resistance and puncture protection
- Attached whistle: Loud enough for emergency signalling, with printed instructions for use
- Compact form factor: Fits easily into hydration vest pockets, waist belts, or jacket compartments
The bright orange colour is a deliberate safety feature — highly visible to rescue teams and fellow runners. The case includes printed emergency instructions, making it useful even for less experienced trail users.
Field Performance and Use Cases
Trail Running and Fell Racing
The bivvy bag meets mandatory kit requirements for UK trail races, including Centurion and Spine Race events. It’s ideal for:
- Sudden weather changes
- Injury immobilisation
- Navigational errors leading to overnight exposure
It’s easy to deploy: unzip the case, unroll the bag, and climb inside. The polythene material traps heat effectively and shields against wind chill. While not breathable, it’s designed for short-term emergency use — prioritising warmth and visibility over comfort.
Fastpacking and Solo Missions
For multi-day runners or solo adventurers, the bivvy bag offers:
- Lightweight backup shelter
- Protection during unexpected delays or route changes
- Peace of mind in remote terrain
It’s not a substitute for a tent or tarp, but it’s a critical safety layer when weight and speed matter.
Group Safety and Coaching
Running coaches and group leaders can carry multiple bivvy bags without adding significant weight. They’re useful for:
- Supporting injured runners
- Creating temporary shelter while awaiting help
- Enhancing group safety compliance
Durability and Reusability
While marketed as a single-use emergency item, the Harrier bivvy bag can be reused with care:
- Avoid tearing during deployment
- Air-dry after use to prevent mildew
- Store loosely to preserve material integrity
The outer case protects the polythene bag from abrasion and punctures, and the whistle remains functional across multiple outings.
Comparison Table: Harrier vs Other Emergency Bivvy Bags
| Product | Weight | Size (Packed) | Visibility | Price | Best Use |
|---|---|---|---|---|---|
| Harrier Emergency Shelter Bivvy | 129g | 10 x 7 x 7 cm | High (orange) | £11.99 | Trail running, race kit |
| Lifesystems Thermal Bag | 220g | 14 x 10 x 4 cm | High (orange) | £13.95 | Hiking, general emergency |
| SOL Emergency Bivvy | 108g | 8 x 6 x 4 cm | High (orange) | £19.99 | Lightweight backpacking |
| OMM Thermal Bag | 120g | 12 x 8 x 5 cm | Moderate | £12.00 | Mountain races, ultras |
The Harrier bivvy bag offers excellent value and race-specific design, making it ideal for UK trail runners who need compliance, visibility, and warmth in a minimalist package.
Pros
- Ultralight and compact — fits any running vest
- Bright orange for high visibility in emergencies
- Includes whistle and printed instructions
- Meets race kit requirements for UK trail events
- Tear-resistant and windproof polythene
- Affordable price point for all runners
Cons
- Not breathable — condensation may build up
- Single-use design (though reusable with care)
- No insulation — relies on body heat retention
- No zip or drawcord closure — open-ended design only
Final Verdict
The Harrier Trail Running Emergency Shelter Bivvy Bag is a smart, affordable, and race-ready piece of safety gear. It’s not designed for comfort or long-term shelter — but it excels at what it’s built for: keeping runners warm, visible, and protected in emergency situations.
Whether you’re prepping for your first ultra or refining your fastpacking kit, this bivvy bag deserves a permanent spot in your vest. It’s lightweight enough to forget about — until you need it most.
Rating: 9.3/10
Best For: Trail runners, ultramarathoners, fastpackers, race compliance
Avoid If: You need breathable or insulated shelter for extended use
Check out the Harrier emergency Shelter Bivvy Bag on the Harrier website here.
