The side airbags and curtain airbags ARE DESIGNED TO DEPLOY when…
The side airbags and curtain airbags are designed to deploy when the vehicle suffers a moderate-tosevere side impact to the middle of the passenger compartment.
The typical condition is shown in the illustration.

The seat belts in your vehicle are your primary means of protection in a collision. The SRS side airbags and curtain airbags are designed to provide additional protection. Therefore, for your safety and the safety of all occupants, be sure to always properly wear your seat belts.
See also:
Warning display list (when the ignition switch is “ON”)
...
During cold weather
To ensure proper operation of the washers at low temperatures, use a fluid containing
an anti–freezing agent. ...
3-point type seat belt (with emergency locking mechanism)
This type of belt requires no length adjustment.
Once worn, the belt adjusts itself to the movement of the wearer, but in the
event of a sudden or strong shock, the belt automatically locks to hold ...
