Heat, Cold, and Relaxation: The Science Behind Your Hot Tub and Cold Plunge

The Heat Revolution: Saunas Leading the Pack

Twenty minutes in the sauna this morning, hot tub tonight after dinner, maybe a cold plunge tomorrow. If this sounds like your typical week at Hedley House Hotel, you're onto something science is just catching up with.

After nearly three decades of watching guests unwind in our facilities, we're not surprised researchers are confirming what we've seen every day: heat and cold therapy work. But the latest studies reveal some fascinating details about how.



Regular sauna use keeps making headlines, and for good reason. Recent research from the American Journal of Physiology shows that people who use saunas regularly see measurable improvements in cardiovascular function and lower blood pressure .

What's happening in there isn't magic – it's biology working overtime. Your core temperature rises, blood vessels dilate, heart rate increases. It's like gentle cardiovascular exercise without moving a muscle. Finnish researchers have tracked thousands of people for decades and found regular sauna users have significantly lower risks of heart disease and stroke.

But here's what caught our attention: the benefits extend far beyond heart health. Studies show sauna use triggers the release of heat shock proteins, cellular repair mechanisms that help your body handle stress better. Regular sessions also boost growth hormone production and may even help clear cellular waste from your brain during sleep.

The sweet spot appears to be 15-20 minutes at temperatures between 80-100°C, three to four times per week. Start shorter if you're new to it.

Cold Therapy: The Ice Bath Revolution

Cold water immersion has gone from athletic recovery tool to mainstream health practice, and the research explains why people can't stop talking about it.

A comprehensive review published in PLOS ONE analysed data from over 3,000 participants across multiple studies . The findings reveal some interesting patterns about how your body responds to cold exposure.

Immediately after cold immersion, inflammation markers actually increase. Your body is responding to the shock. But 12 hours later, stress levels drop significantly. It's like your system learns to handle stress more efficiently.

The immune benefits intrigue researchers most. One large study found people who took cold showers for 30 days had 29% fewer sick days from work. They caught the same number of colds, but recovered faster .

Cold exposure also triggers massive releases of norepinephrine – up to five times normal levels. This isn't just about alertness. Norepinephrine acts as an anti-inflammatory agent and may explain why people report improved mood and mental clarity after cold exposure.



The research suggests water temperatures below 15°C for 30 seconds to 2 minutes provide benefits without unnecessary risk. Regular exposure seems more important than duration.

Hot Tubs: The Unexpected Champion

Recent research from the University of Oregon delivered a surprise: hot tubs may actually outperform saunas for certain health benefits .

When researchers compared hot tubs, traditional saunas, and infrared saunas, hot water immersion raised core body temperature most effectively. Why? In water, you can't cool down through sweating. Your body has to work harder to regulate temperature, creating stronger physiological responses.

The cardiovascular benefits particularly impressed the research team. Hot tub use increased blood flow more dramatically than sauna sessions. The enhanced circulation helps explain why people with arthritis often feel better after soaking – increased blood flow reduces joint stiffness and delivers nutrients to damaged tissue.

Sleep improvements also appear more pronounced with hot tub use. The temperature drop after leaving warm water triggers your body's natural sleep preparation mechanisms. Studies using the Pittsburgh Sleep Quality Index showed measurable improvements in sleep quality after regular hot tub sessions.

For people who struggle with traditional exercise, hot tubs offer particular promise. A 2018 study found that one hour in a 40°C hot tub burns similar calories to a 30-minute walk, while also improving insulin sensitivity and glucose metabolism.



The Contrast Effect: Why Hot and Cold Work Better Together

The real magic might happen when you combine both approaches. Contrast therapy – alternating between hot and cold – creates a pumping action in your blood vessels. Capillaries expand in heat, contract in cold, then expand again.

This vascular exercise appears to improve circulation long after your session ends. Athletes have used this principle for decades, but researchers now think it benefits anyone dealing with inflammation or recovery issues.

Our observation after 29 years: guests who use both our hot tub and take cold showers report feeling more energised and sleeping better than those who stick to just one approach.

Getting Started Safely

Start conservatively. Your first sauna session shouldn't exceed 10 minutes. Begin cold therapy with 30-second cool showers before progressing to ice baths.

Stay hydrated – both heat and cold exposure increase fluid needs. Avoid alcohol before sessions, which impairs your body's temperature regulation.

Listen to your body. Dizziness, nausea, or skin colour changes mean it's time to stop. Always consult healthcare providers if you have cardiovascular issues, are pregnant, or take medications that affect blood pressure.

The research keeps expanding, but one thing stays consistent: regular thermal stress, whether hot or cold, appears to make us more resilient. Your body adapts, becomes more efficient at handling challenges.

Maybe our guests have been conducting their own research all along. They just call it relaxation.

At Hedley House Hotel, our wellness facilities include a modern hot tub, Luxury Sauna and Cold plunge. Located just minutes from York city centre with secure parking.

Call 07428 917515 to book your stay.