An SOS emergency button is a feature on select dash cam models — including some Nexar cameras — that provides a one-button emergency response beyond what standard dash cam recording offers. It's one of the least-discussed features in dash cam reviews and one of the most consequential in real-world use.
Here's exactly what it does, when it activates, and why it matters particularly for solo drivers and long-distance travelers.
What an SOS Button Does
When the SOS button is pressed, or when it's triggered automatically by a severe collision event, the camera initiates a coordinated response:
- Footage lock: The current and preceding footage is immediately locked and protected from overwrite.
- Cloud upload: The event clip is prioritized for immediate upload to cloud storage, bypassing the normal queue.
- Location broadcast: The camera's current GPS coordinates are transmitted to the Nexar app and to pre-configured emergency contacts.
- Emergency contact notification: Up to three configured contacts receive a push notification containing the location coordinates, a timestamp, and a link to the event footage once uploaded.
- Emergency services option: The Nexar app presents an option to call 911 directly from the notification interface, with the GPS location pre-populated for the dispatcher.
Automatic vs. Manual SOS Activation
The SOS feature has two activation modes:
Manual activation: The driver presses the physical SOS button on the camera body, or triggers it from the Nexar app. This is used when the driver is conscious and needs to alert contacts quickly — for example, after being in an accident and not having time to call individually, or in a roadside emergency where they need contacts to know their location.
Automatic collision detection (Crash Detection): When the G-sensor detects an acceleration spike above the severe collision threshold — significantly higher than the standard event trigger — the camera can automatically initiate the SOS sequence. This activates the emergency response without the driver needing to press anything.
Automatic activation is configured separately from manual SOS. In the Nexar app: Settings → Safety → Crash Detection. The sensitivity threshold for automatic activation is set deliberately high to avoid false SOS triggers from hard braking or potholes — it's designed to respond to actual collision forces.
Who Benefits Most From SOS
Solo long-distance drivers: If you regularly drive long stretches of remote highway alone, an automatic crash detection SOS means someone knows where you are and what happened even if you're incapacitated.
Teen drivers: Parents who set up their teen's car with a Nexar camera can configure themselves as SOS contacts. If an automatic collision event occurs, the parents receive a notification with location and footage within minutes — not when the teen calls (or doesn't call) an hour later.
Elderly drivers: Similar to teen driver use — family members as SOS contacts provide a passive safety net that doesn't require the elderly driver to remember to call or to have their phone charged and accessible after an incident.
Rideshare drivers: A rideshare driver in a late-night incident has an automatic notification sent to their emergency contact with location — without needing to use the phone while dealing with an accident and potentially difficult passenger.
Setting Up Emergency Contacts
- Open the Nexar app and navigate to Settings → Safety → Emergency Contacts.
- Tap "Add Contact" and enter the contact's name and phone number or email.
- The contact receives a confirmation request — they need to accept to become an active emergency contact. This ensures they're aware of the role and can respond appropriately.
- Configure whether the contact receives notifications for all significant events or only for SOS-level events. For family monitoring purposes, all events is appropriate; for more casual emergency contacts, SOS-only is better.
- Test the notification by pressing the SOS button (a test mode is available that generates a notification without triggering an emergency response) and confirming the contact receives it with the correct location.
Crash Detection Sensitivity
The crash detection sensitivity for automatic SOS needs careful calibration:
- Too sensitive: Hard braking, potholes, or speed bumps trigger automatic SOS notifications. Emergency contacts receive false alarms. After a few false alarms, contacts begin to ignore notifications — defeating the purpose.
- Too low: Actual collision events don't trigger automatic detection. Manual SOS remains available, but the automatic backup for incapacitated drivers isn't working.
The recommended approach: start at the medium sensitivity setting. Review the events section of the app after 2–4 weeks to see what types of events are being flagged. If potholes and hard brakes are generating near-SOS triggers, lower sensitivity. If you've had a genuine hard impact that wasn't auto-detected, raise it.
What to Do After an Automatic SOS Triggers
If the SOS activates automatically after a collision:
- The Nexar app on your phone shows a notification — you can dismiss it if you're conscious and not in danger ("I'm okay" response cancels the emergency contact notification chain).
- If you don't dismiss it within a configurable window (typically 30–60 seconds), emergency contacts receive the full notification.
- Emergency contacts who receive the notification can call you directly or call 911 with your GPS location.
- The locked footage is available to emergency responders via the shared link once uploaded.
SOS Button Physical Location
On Nexar cameras equipped with the SOS button, it's a distinct physical button on the camera body — typically on the side or bottom of the unit, separate from the record/format/reset buttons. It may be labeled "SOS" or marked with an emergency symbol. In some models, the button is recessed to prevent accidental activation during normal handling.
Familiarize yourself with its location when you first install the camera. In an actual emergency, you shouldn't need to look for it.
The Broader Case for Emergency Features
The SOS button represents a shift in what a dash cam is. A recording device captures what happened. An emergency-response device communicates what happened, where, and that help is needed — without requiring the driver to take any action after the incident.
For most routine drivers, the SOS button will never be used. For the driver who has a medical event at the wheel on a rural highway at 2 AM, it's the reason someone finds them. The value isn't in the frequency of use — it's in what happens in the rare scenario where everything else fails.