Safety
If in Doubt, Get Out
Heat and cold exposure can both be dangerous. Tidal Contrast is designed to make sessions safer, but it cannot make them safe for everyone, and it is not a medical device.
If someone faints, has chest pain, is confused or very sleepy, cannot stop shivering or is struggling in the water, call 999 or 112.
Talk to a Doctor First
Before you start, talk to a doctor if you:
- have a heart condition, high or low blood pressure, or have had a stroke
- have asthma, or have fainted before
- are pregnant
- take medication that affects blood pressure, heart rate or temperature, such as beta blockers
- have a condition affecting circulation, nerves or skin sensation
The app asks about these on first launch. Any yes shows “talk to your doctor first” and needs your confirmation.
Skip Today
Leave the heat and the cold for another day if you:
- have been drinking alcohol
- feel unwell or feverish
- feel dizzy, or very tired
This is the three-tap daily check before every session. Any yes makes today a skip day.
Cold Water
- Never swim or immerse alone. Cold water can cause sudden loss of control of breathing and movement.
- Do not do breath holds or fast breathing before or during a session near water. The app never prompts them.
- Get in slowly, let your breathing settle, and keep sessions short. The app caps your time and warns you before the limit.
- Plan how you will get out and get warm before you get in.
- In open water, check the entry and exit, the current and the depth, and remember conditions change after rain.
Rewarming
Your body can keep cooling after you leave the water. Dress warm, keep moving gently, have a warm drink, and avoid very hot water straight away. Get medical help if you feel confused, very sleepy, or cannot stop shivering.
Sauna and Steam
- Drink water before, between rounds and after. Step out at once if you feel dizzy, faint, sick or have chest pain.
- Keep rounds short at first, rest between them, and stand up slowly when you leave the heat.
- Do not go straight from a hot sauna into cold water unless a doctor has said that is right for you.
- Avoid alcohol before heat or cold.
Wearing an Apple Watch in the sauna is an opt-in, off by default. Apple publishes operating limits for its Watches, and high sauna temperatures can go beyond them. Check Apple’s guidance for your model and decide for yourself; you use it at your own risk.
A Helper, Not a Lifeguard
Alerts depend on your Watch, your phone, your settings and your signal, and they can fail. Remote spots often have no signal at all. Do not rely on the app to keep you safe.