What are Shock Proteins?
Many of us have built our lifestyles around a narrow band of temperature. Central heating. Air con. A car to bridge the gap.
We have domesticated our environment as thoroughly as we have domesticated our food and ourselves.
But your body has not evolved for perpetual comfort. It is designed for seasons and the weather of a world that is sometimes too hot and sometimes too cold.
When we meet those edges sensibly, your cells respond by making “shock proteins”: little molecular chaperones that keep you protect cells under stress.
Amber enjoying the benefits of hot water in Ireland
Thermal Variety is Human
Heat and cold are not just “stress”. In the right dose, they are information. They remind your nervous system, metabolism, and mind that you are alive and adaptive, not fragile and shrink-wrapped.
This is not a call to suffer for its own sake. It is a call to return to nature’s temperature range.
When your body experiences meaningful heat stress, it activates the heat shock response, increasing the production of heat shock proteins (HSPs).
Cold exposure triggers a different set of responses, including “cold shock” proteins, which researchers have investigated for roles in cellular protection.
It’s not as simple as saying healthy people have higher shock proteins. A safer statement is: health is linked to a well-regulated stress response, and shock proteins are a part of that.
George swimming in the Afon Ceidiog that runs through our garden
Practical Exposure in Nature
If your goal is wellbeing and reconnection, the sweet spot is usually small, repeatable exposures that finish feeling steady, not shattered.
Cold water and cold air can be powerful, but they are also unforgiving.
– Cold shower: finish a normal shower with 15 to 30 seconds of cool water, building slowly over weeks.
– Brisk walk: a walk with slightly lighter layers than you would normally choose, so you feel the cold briefly, then warm yourself through movement.
– Cold water swimming: treat it like a skills practice, not a test of character. Keep it short, choose controlled entry, and prioritise a safe exit and rewarming. Read more on the safety of cold water immersion here.
If you lift weights, frequent cold water immersion straight after resistance training may reduce muscle hypertrophy over time. If building muscle matters to you, consider separating cold water from strength sessions (for example, do cold on rest days).
Heat exposure can be as simple as a summer hike at the right time of day, or as structured as sauna use, if you have access.
– Micro-exposure: add a few minutes of extra warmth before, during or after exercise (wear an extra layer, train in a warm room), then cool
– Natural sunlight: seek safe summer sunshine (track safe sun time with dminder).
– Sauna: start short and moderate. Build tolerance, not heroics.
Sauna use has observational links with lower risks of fatal cardiovascular outcomes and all-cause mortality in a long-running Finnish study. Be cautious if you have low blood pressure or certain heart conditions, and leave if you feel dizzy or unwell.
Fresh snow in our garden
Remember
You do not need extremes. You need relationship.
A regular practice of meeting the day as it is, instead of forcing the day to match your thermostat.
This month, try:
– Three short cold experiences (cool shower finish, brisk cold walk, or cold air on the face at sunrise).
– Three short heat experiences (an intense workout, a gentle sauna, or simply dressing warmly and moving).
Keep it safe, keep it small, and let your body remember what it may have forgotten.
If you are pregnant, have cardiovascular disease, uncontrolled hypertension, a history of fainting, or any condition that could make temperature stress risky, get medical advice before experimenting.
