Tim and Bonnie Mawby change into their bathing suits, grab a couple of towels and head straight outdoors. Within seconds, the Centerville couple are sitting chest-deep in the swirling 102 degree waters of their hot tub. Under the canopy of stars, with a couple of cold drinks in their hands, they’ve found a quiet, relaxing retreat right in their own backyard.

Now this is the way to go through the long, cold months.

Winter is the best time to appreciate an outdoor hot tub, proclaim the Mawbys and scores of other homeowners who sing the praises of their “snow” tubs.

At least 80 percent of buyers install their hot tubs out of doors; the fall and winter months are popular times for using them, says John Ball, owner of Aurora Home Energy Recreation Store.

“The time to use it is in the winter,” agrees Don Somers, owner of Classic Cedar Homes & Sunrooms . “It’s just glorious.”

Here’s how he describes the winter-time experience: “You can look up at the stars. The air is fresher in the winter. You are warm in the water and the steam in rising up all around you.”

While you’re comfortably warm sitting in the water, “you can actually get icicles in your hair,” he says.

“I keep the water around 100 degrees and if its 90-degree weather, I couldn’t stand it,” Somers says. In his opinion, the 70-degree temperatures in most houses make it too warm to be comfortable using a hot tub indoors.

“The steam in a house isn’t a good idea either,” he adds.

The larger hot tubs are the ones people buy for outdoor installation, according to Ball. These models range in price from $2,500 to $8,000, depending on the size and style.

An outdoor hot tub that is kept filled with warm water will add $15-45 to your heating bill a month during the winter, Ball says.

By contrast, during spring and summer months, which require less heat to maintain water temperature, the heated tub will add $10-15 to your utility bill.

While many people buy hot tubs for purely recreational use, some swear by the therapeutic value of warm swirling waters.

Dr. Sean Convery, medical director of Miami Valley Hospital’s Sports Medicine Center, often recommends whirlpool treatments for people with joint problems, arthritis or sore muscles.

He warns against using warm water treatments for acute injuries, such as sprained ankles, which could worsen the damage.

For homeowners who like to use their outdoor hot tubs in the cold months, Convery offers this advice:

Be careful when you’re getting out of the hot tub to avoid slipping on the wet surface of the deck or patio.

To avoid respiratory problems, don’t linger outdoors once you get out of the water. Bundle up and head straight indoors.

While the warm and cool temperature conrast shouldn’t be a problem for people in good health, anyone with high blood pressure, heart problems or on medication should check with their doctors before using a hot tub.

Convery recommends limiting time in the hot tub to half hour sessions; if you feel faint or light-headed, get out of the water.

When they bought their hot tub last year, the Mawbys never considered installing it indoors. “We had no desire to have it inside. It’s no fun,” Bonnie says.

Indoor temperatures are just too warm to sit in a hot tub. “But if it’s 30 degrees outdoors, you’re comfortable,” she says.

While they use their hot tub on on cool summer nights, they wait for the temperatures plummet to really start enjoying their new addition to their backyard.

On winter nights, when the temperatures are so cold you can see your breath in the frigid evening air, the couple almost feels transported to Vail . . . or Aspen.

“You can almost create an atmosphere of being at a ski resort,” Bonnie Mawby says. “The atmospshere just isn’t the same in the summertime.”