Every year, emergency room doctors treat 84,000 people for lawn mower accidents. To avoid a visit to the ER, follow these tips and prevent mower accidents.

Here are seven mower-safety tips from Underwriters Laboratories, a not-for-profit product safety testing company. 

1. Read your lawn mower’s owner’s manual and know how to stop the machine instantly in an emergency.

2. Always start the mower outdoors. Don’t run the mower where carbon monoxide can collect, such as in a closed garage, storage shed, or basement.

3. Don’t operate an electrically powered mower on wet grass.

4. Keep your hands and feet away from the mower’s blades. Never reach under the mower while it’s running—make all adjustments with the motor off.

5. Don’t leave a running lawn mower unattended.

6. Make sure your shoes provide good traction and have sturdy soles to resist punctures and protect toes. Never work barefoot, in sandals, or in canvas shoes.

7. Mowers can fling rocks at up to 200 miles per hour. Keep other adults, children, and pets clear, and wear long pants to protect your legs.