How Hot Can The Hot Tub Get?
The water in a spa or hot tub should never exceed 40C (104F). Water temperatures between 38C (100F) and 40C (104F) are considered safe for a healthy adult. Lower water temperatures are recommended for extended use (exceeding 10 – 15 minutes) and for young children. CAUTION: Before entering a spa or hot tub, the user should measure the water temperature with an accurate thermometer since the tolerance of water temperature-regulating devices may vary as much as +/-3C (5F).