After today, the temperatures begin to show a warming trend — all the way to the mid 20s for the weekend. That’s not balmy yet, but it’s an improvement from the teens.

In any event, National Fuel issued some safety reminders worth noting during a deep freeze. In a news release issued Tuesday the company noted that natural gas furnace exhaust vents can become easily clogged by debris, ice or snow, causing the furnace to shut off or operate inefficiently. Blocked vents also can lead to a buildup of carbon monoxide (CO) gas inside a residence. “CO is a colorless, odorless and dangerous gas produced when fuel is burned without enough air for complete combustion,” the company said. “CO poisoning can cause extreme illness and death. Symptoms include fatigue, coughing, headache, irregular breathing, dizziness, overall paleness, nausea and cherry red lips and ears. Open windows and doors, move outside and call 911 immediately if experiencing symptoms.”

Emergencies can be avoided by:

— Having a professional inspect and test chimney and heating equipment annually.

— Installing at least one CO detector.

— Never using a gas oven or stovetop for heating.

— Never running a gasoline engine, generator or automobile in an enclosed space.

National Fuel says if a rotten-egg natural gas odor is present, leave the premises immediately and call its emergency line, 1-800-444-3130, from a different location. If you smell gas outdoors, call National Fuel’s emergency number and provide the address nearest to the site of the odor.

Spring will be here in less than two months. Until then, stay warm — and safe.