A range hood pulls grease, smoke, and moisture out of the kitchen, but grease-clogged filters stop it working and become a fire hazard. Cleaning it is quick and worth doing regularly.
Clean the filters
Metal mesh grease filters can be soaked in hot soapy water (a little degreaser or baking soda helps) and scrubbed, or many are dishwasher-safe. Do this every month or two depending on how much you cook — a saturated filter can't trap grease and is a fire risk.
Wipe the hood
Degrease the hood surfaces and the area around it, where airborne grease settles into a sticky film. Charcoal filters in recirculating (ductless) hoods can't be washed and need periodic replacement.
Vent outside if you can
A hood that vents outside removes far more grease, moisture, and combustion byproducts than a recirculating one that just filters and blows air back into the kitchen. If your hood vents outside, make sure the exterior flap and duct stay clear.