01
Cheap enough to cover everything
Under $9 a sensor means a clinic can cover every fridge, not just the one holding the most valuable stock.
- Under $9 per sensor
- Clips onto existing fridges and cold boxes
- No technician visit to install
Now deployed across five countries
Never lose a dose to a broken fridge.
Coldwatch is a cold-chain sensor and alert system built for clinics that don't have a smartphone in the building — a breach texts someone who can act on it, in minutes, not at the next supply run.
At a glance
- Sensor cost
- Under $9 per unit
- Network
- SMS — no smartphone or data plan needed
- Battery life
- 18 months on two AA cells
- Alert time
- Under 3 minutes from breach
- License
- Apache-2.0
Deployed at
- Kilifi County Health
- Cox's Bazar Cold Chain
- Andes Rural Clinics
- Sahel Vaccine Network
- Manaus River Depots
The system
Cold-chain monitoring that doesn't assume a smartphone.
Most cold-chain platforms are built for a dashboard someone checks. Coldwatch is built for a fridge nobody's watching at 2am.
02
SMS, not an app
Alerts go out over SMS to a plain phone. No app store, no data plan, no smartphone requirement anywhere in the chain.
- Works on any 2G network
- Alerts under 3 minutes from breach
- Dashboard optional, not required
03
Built with clinic staff
Every threshold and alert format came from clinic staff who'd already lost a shipment once and didn't want to again.
- In use across five countries
- Apache-2.0, self-hostable, no lock-in
- Designed to WHO PQS cold-chain guidelines
Specification
- Sensor
- NTC thermistor, ±0.3°C accuracy
- Reporting
- SMS, every 10 minutes or on threshold breach
- Range
- -30°C to 8°C, configurable per unit
- Power
- 2× AA, 18-month typical life
- Dashboard
- Self-hosted or Lmnfrs-hosted, your choice
- License
- Apache-2.0
Get started
- 01
Attach a sensor
Clips onto any fridge or cold box — no rewiring, no technician visit.
- 02
Pair by SMS
Text a code to register the unit. No app, no smartphone, no data plan.
- 03
Get alerted
A breach texts the clinic and the district office at the same time.
pip install coldwatch-gateway
Protect the next shipment.
District health offices and rural clinics run Coldwatch on fridges they already have. We'll help you size a rollout for free.