Best Cold Plunge Tub: Ice or Chiller, Rigid or Inflatable

Pick a tub that lets you sit upright with water to your shoulders. For most adults that is 75 to 105 gallons, which is the range of the tubs here. Tall users should check the height rating, for example the Lifepro NordPod lists users up to 6 ft 7 in.

Cold water immersion is usually done between about 39 and 59 F (4 to 15 C). A chiller rated for 37 F, like the one in the Primal Health kit, covers that whole range. Start at the warmer end and short sessions, and talk to a doctor first if you have a heart condition or high blood pressure.

About 85 to 90 lb of ice cools 77 gallons from 60 F to 40 F, before any heat gain. That comes from 8.34 lb per gallon of water and about 144 BTU absorbed per pound of ice melted. A lid and an insulated tub cut how often you have to add more.

A chiller is worth it if you plunge most days, because it replaces buying or making ice for every session. At 85 or more pounds of ice per cooldown, daily plunging adds up fast. If you plunge once or twice a week, ice plus an insulated tub costs less to start.

It depends on the chiller's wattage and how many hours a day the compressor runs. As an example, a chiller drawing 500 W for 8 hours a day uses 4 kWh, about 69 cents a day at the 2025 U.S. average of 17.3 cents per kWh. Use the wattage on your chiller's label for your own number.

Ice Barrel says to change the water every 4 weeks, or as needed, using a water stabilizer in between. A tub with a filtered chiller loop keeps water circulating, but still needs periodic changes. A lid keeps debris out between sessions.

Water weighs 8.34 lb per gallon, so 77 gallons is about 642 lb and 105 gallons is about 876 lb, before you climb in. Most ground-floor slabs and garages handle that easily. On an upper floor or a deck, check the load rating first.

Rigid and insulated if you want the water to stay cold longer and the tub to last for years. Inflatable drop-stitch tubs cost less, fold flat, and suit people who plunge a few times a week. Both kinds can be paired with a chiller if they have fittings for it.

Yes, the Lifepro NordPod and the Primal Health kit are both listed for indoor or outdoor use. Outdoors, use a lid to keep out debris and sun. In freezing climates, drain the tub and chiller lines or move them inside so water does not freeze in the fittings.

Most people start with 1 to 3 minutes and work up to a few minutes per session. Colder water calls for shorter sessions. Never plunge alone if you are new to it, and get out if you start shivering hard or feel numb.