Hot Springs for Cold Sensitivity | 4 Spring Types Explained

4 Spring Types Indicated for Cold Sensitivity

Japan's Ministry of the Environment lists four spring types with official bathing indications for peripheral circulatory failure (cold sensitivity, poor circulation):

• Chloride springs: Form a heat-retaining salt film on the skin — known as the "heat spring" (熱の湯)
• Bicarbonate springs: Dilate skin capillaries and improve local blood flow
• Sulphate springs: Support arterial circulation and peripheral recovery
• Carbon dioxide springs: CO₂ absorbed through the skin dilates blood vessels without raising core body temperature — the "heart-friendly bath"

Bathing tips for cold sensitivity

1. Splash water on limbs before full immersion to prevent blood pressure spikes
2. Ideal temperature: 40–41°C — above 42°C stimulates the sympathetic system and can worsen cold extremities
3. CO₂ springs run at 38–40°C; soak 15–30 minutes to maximise capillary dilation
4. Dress quickly after a chloride spring bath to preserve the heat-retaining coating