Do you own a home that has a fireplace? How long has it been since you had your fireplace cleaned and inspected by a professional? If you're like a lot of people, you probably tell yourself every year that you'll get to it next year. Next year comes and you'll take care of it the year after. This continues for some time until you can't remember how long it's been since you had your chimney swept out and/or inspected. When you're not using your fireplace at all, this isn't so bad. But if you're using the fireplace on even a semi-regular basis, you need to have it checked out ASAP for the following reasons:
Creosote buildup: The smoke that rises from your chimney when you burn logs contains various tarry substances and microscopic particles of unburnt wood. Most of these rise harmlessly into the sky but some of these particles condense on the sides of the chimney. Without any professional chimney services to clean away this buildup, it will eventually get thick enough that it will catch on fire when you use the fireplace. Chimney fires can be exceptionally dangerous because you won't always realize that one has started and could only have a few seconds to escape your home once you've noticed the fire.
Damage: As you most likely learned in school, heat causes most substances to expand and they will then contract again once they have cooled off. Despite the solid nature of the materials that make up your chimney, it is also subject to these laws of physics. You might not see it happening yourself, but this practically invisible expansion and contraction will weaken your chimney over time. Without any chimney services inspecting and repairing your chimney as-needed, you could run the serious risk of eventually having a structurally unsound chimney that will need to be replaced before it can be used.
Blockages: Modern chimneys often have caps and/or small openings that are blocked off by something like wire mesh to allow the smoke to get out and to prevent small animals from entering. Unfortunately, these caps can get dislodged by the wind and sometimes the mesh can get damaged/destroyed by various means. When this happens and isn't fixed by your local chimney services, small animals and even birds can enter your chimney and get stuck there. If they don't then enter your home or aren't removed by other means, they can block the smoke and/or may catch fire due to the heat.