Hot Tubs & Spas
Hot tubs are relaxing, but they bring several risks: overheating, drowning, electric shock, chemical burns and germs that grow in warm water. Most problems come from long soaks, unsupervised children, alcohol and poor maintenance, and all are easy to prevent.
- Homeowners
- Renters
- Families
Water temperature and soak time
- Keep the water at 104°F (40°C) or lower. That is the maximum most standards set for spas. Many people are more comfortable at 100°F to 102°F.
- Limit a soak to about 15 minutes at a time at the top temperature, then cool off. Longer soaks can cause overheating, dizziness, fainting and heat stroke. See Extreme Heat.
- Get out right away if you feel dizzy, nauseated, lightheaded or too hot.
- Check the temperature with a thermometer. Don’t trust the display alone.
Who should be careful
- Children are at higher risk of overheating, and small children can drown in a few inches of water. Only allow them in with an adult watching, and use lower temperatures and shorter times.
- Pregnant women: a rise in body temperature, especially in early pregnancy, may be harmful. Talk to your doctor before using a hot tub.
- People with heart disease, high or low blood pressure, diabetes or on certain medications should ask a doctor first.
- Alcohol and drugs raise the risk of drowning and overheating. Don’t soak after drinking, or while using sedating medicine.
Preventing drowning and entrapment
- Lock the cover whenever the tub isn’t in use. A locking, rigid cover keeps children and pets out, and keeps heat in. A flimsy cover is not a barrier.
- Never leave a child alone in or near a hot tub, even for a moment. Keep gates and doors to the yard closed. See Pool & Water Safety.
- Make sure all drains have anti-entrapment covers that meet the federal Pool and Spa Safety Act (the VGB Act). Strong suction can hold a swimmer or a child’s hair or body against a drain.
- Tie back long hair and don’t sit on or near suction outlets. Know where the emergency shutoff is.
- Learn CPR. See Home First Aid.
Electrical safety
- Hot tubs must be wired to code by a licensed electrician, with GFCI protection and bonding. Many places require a permit and inspection.
- Never use extension cords, space heaters, radios or hair dryers near the tub. Keep outlets, lights and devices away from the water’s edge, as the code requires.
- If you feel a tingle in the water, get out and shut off power at the breaker. Don’t use the tub until an electrician checks it.
- Test the GFCI regularly. See Home Electrical Safety.
Water quality and germs
- Warm water makes it easy for germs to grow. Keep the sanitizer (chlorine or bromine) and pH in the range your tub manufacturer gives, test them often and change the water on a regular schedule.
- Legionella bacteria can grow in poorly maintained hot tubs and cause a serious pneumonia called Legionnaires’ disease or a milder illness, Pontiac fever. Breathing in mist from contaminated water spreads it.
- Hot tub rash (folliculitis) from Pseudomonas bacteria shows up as itchy red bumps a day or two after soaking.
- Shower before you get in, keep the filter clean and don’t soak if you have diarrhea or open wounds.
Chemicals
- Don’t mix different pool or spa chemicals, and never add them to each other. Toxic gas or fire can result. See Household Chemicals.
- Add chemicals to water, never the reverse, and use only the amounts on the label. Don’t add them while people are in the tub.
- Wear gloves and eye protection when handling chemicals, and store them locked, dry and away from fuels and children.
Other tips
- Use non-slip steps and handrails, and keep the area around the tub clean and dry. Wet tile and decks are slippery.
- Make sure the deck or pad can hold the weight. A full tub can weigh several tons. See Deck & Railing Safety Checks.
- Don’t use glass containers.
- Keep a phone and a first aid kit near the tub.
Hot tub checklist
- Water at 104°F or lower; soaks kept short
- Cover locked when not in use; children supervised at all times
- Drain covers are anti-entrapment; hair tied back
- GFCI tested; no cords or devices near the water
- Sanitizer and pH tested; water changed on schedule
- No alcohol; people at risk have asked their doctor
Standards & references
Last updated: