Safety
Hot Spring Safety: 12 Rules for a Safe Soak
Last updated October 6, 2026 · 4 min read
A hot spring soak is one of the most relaxing things you can do outdoors. It is also one of the few places where the water itself can hurt you. Every year people are burned at thermal features, faint in hot pools or get lost walking out in the dark. Almost all of these accidents are avoidable.
These rules apply whether you are paying for a resort pool or hiking to a primitive spring in a national forest.
1. Test the water before you get in
Never step or jump straight into a pool. Put your hand in first, and if you have a thermometer, use it. Temperatures in a natural pool change from day to day with creek levels, rain and how people have moved the rocks. A pool that was perfect last month can be scalding today.
As a guide, 98°F to 104°F (37°C to 40°C) is the comfortable range for most adults. Water above about 112°F (44°C) can burn, and water at 140°F (60°C) can cause serious burns in seconds. Our soak temperature guide explains each range.
2. Respect the source
The temperatures listed in this directory are usually measured where water leaves the ground. Many sources are near boiling. Never put your hands or feet into a vent, a bubbling pool or a stream coming straight from the source.
In geyser basins and thermal areas, the crust beside a pool can be a thin shell over boiling water. Stay on boardwalks and marked paths. In Yellowstone and some other parks, entering thermal features is illegal for exactly this reason.
3. Keep your head above water
Naegleria fowleri, often called the brain-eating amoeba, lives in warm fresh water, including some natural hot springs. It is extremely rare, but infection through the nose is almost always fatal. You cannot catch it by swallowing water.
- Keep your head above the surface.
- Do not dive, dunk or splash water onto your face.
- Consider a nose clip at undeveloped springs.
Chlorinated, well-maintained pools carry far less risk.
4. Drink water, and skip the alcohol
Hot water makes you sweat more than you notice, especially at altitude or in dry desert air. Drink before, during breaks and after your soak.
Alcohol and hot water are a bad mix. Both lower blood pressure and both dehydrate you, which leads to dizziness and fainting. Many hot spring drownings and falls involve alcohol.
5. Limit your time in hot water
In water around 104°F, 10 to 20 minutes is a sensible limit before taking a break. Sit on the edge or stand in the cool air, then go back in if you feel fine. Get out right away if you feel dizzy, nauseous, confused or your heart is racing.
6. Stand up slowly
Blood pressure drops while you soak. Standing up fast can make you light-headed just as you step onto wet, slippery rock. Sit up first, wait a few seconds, then climb out using your hands.
7. Wear shoes with grip
Algae, mineral crusts and wet travertine are slippery. Sandals with a good sole or water shoes help on the walk in and around pools. Bring a headlamp if there is any chance you will walk back after dark.
8. Know who should check with a doctor first
People who are pregnant, have heart disease, high or low blood pressure, diabetes or take medicines that affect heat tolerance should get medical advice before soaking in hot water. Young children heat up faster than adults, so keep their soaks short and in cooler pools.
9. Check the weather and the road
Many springs are reached by unpaved forest roads that close in winter or become impassable after rain. Desert springs can be dangerously hot to hike to in summer. Riverside pools flood when snowmelt raises the river. Check road and river conditions with the land manager before you go.
10. Tell someone where you are going
Remote springs often have no phone signal. Leave your plan with a friend, carry more water and food than you think you need, and turn around if conditions look wrong.
11. Watch for wildlife and bugs
Bears, moose, elk and bison all use thermal areas, especially in winter. Give animals space. Ticks and mosquitoes like the warm, wet ground around many springs, so check yourself afterward.
12. Leave it as you found it
Pack out all trash, do not use soap or shampoo in natural pools, and do not dig new pools or move rocks in ways that damage the site. Many springs have been closed because of litter and damage. See our hot spring etiquette guide for the unwritten rules.
Quick safety checklist
- Water to drink and a towel
- Shoes with grip and a headlamp
- A thermometer, or at least a careful hand
- Warm layers for after your soak
- A bag for your trash
- Someone who knows where you are
Frequently asked questions
Are hot springs safe to swim in?
Most are safe to soak in if you follow simple rules: test the temperature, keep your head above water, stay hydrated, skip alcohol and limit time in very hot water. The risk is higher at remote, undeveloped springs.
Can you get a brain-eating amoeba from a hot spring?
It is possible but extremely rare. Naegleria fowleri lives in warm fresh water and causes infection only when water goes up the nose. Keep your head above water, do not dive or splash, and consider a nose clip at natural springs.
How long should you sit in a hot spring?
At around 104°F (40°C), 10 to 20 minutes at a time is a common limit. Cool down between soaks and drink water. In cooler water you can stay longer.
Who should not use hot springs?
People who are pregnant, have heart conditions or low blood pressure, or take medication that affects heat tolerance should ask a doctor first. Young children overheat faster than adults and need close supervision.