Dr. Craig Heller, Professor of Biology at Stanford University and a world expert on the science of temperature regulation. His research focuses on topics such as the effects of body temperature on physical conditioning and performance, and neurological conditions such as Down syndrome and Alzheimer’s disease.
In this episode of Huberman Lab, Dr. Huberman hosts Dr. Craig Heller to break down the science of temperature regulation and how temperature affects the body and brain. Dr. Heller also provides tips on how to leverage cold to reverse fatigue-induced brain fog, performance, and recovery.
Host: Andrew Huberman (@hubermanlab)
We have built-in mechanisms to cool our body or send signals for natural heat loss if we’re hot
We have an internal thermostat is collecting information from the whole body
Do not use sponges or cold towels on the back or neck: information to the brain is coming from the body; putting a cold towel on the neck is putting a cold stimulus in the brain which can falsely lead you to believe you are recovered but the brain is still hot
To cool the brain: you can have a cooling effect on the brain by pouring water over the head
Heating and cooling of the brain can lead to brain fog: rising of body temperature can induce immediate reduced cognition when sufficiently heated
You can feel cool through the use of ice cubes, cold towels, etc. and still be dangerously overheating internally
Symptoms of hypothermia: you stop sweating, extreme exhaustion, elevated heart rate, generally feeling miserable – symptoms have a slow onset and are difficult to relate to danger, so people tend to push through (even to the point of death as seen when athletes collapse in practice)
First, you get a shock which translates into a shot of adrenaline
Cold stimulates vasoconstriction which causes heat loss
The fundamental difference between cold shower versus cold immersion: cold bath develops boundary layer (so the body feels enveloped in cold)
Cooling decreases swelling of the brain
Cooling the face, hands, and bottom of your feet will cool you twice as fast as anywhere else
The most immediate impairment of muscle fatigue is a rise in temperature of muscle, causing “failure” of rep
Take a cold shower (just a few minutes) before tough exercise to increase the capacity of body mass to absorb excess heat; this will cause your body to delay sweating which can allow you to push harder
Loosen grip on handlebars (e.g., bicycle, ski erg, rower, etc.) when possible because we have heat sensors on the palms of our hands
Heat on the hands can hinder performance: exercise gloves impede heat loss from hands (just like socks impede heat loss from feet)
When cooling hands, you want to get hands cool to the touch – not ice-cold which will induce vasoconstriction of the exact portals you’re trying to cool
Check outwww.coolmitt.com to receive alerts about their public release
Anabolic steroids increase performance 1% per week – cooling has been shown to increase performance by 300% in one week
The best way to measure core temperature is esophageal (but this isn’t practical at home)
Tympanic (ear) temperature is the most accurate at-home test but the laser needs to be pointed in the right place
If you are experiencing hypothermia: try using warm pads or hot water bottles on your feet
Wearing a heat cap in cold weather can reduce heat from escaping and warm you up but you want a good knit with some breathability
Shivering is an adaptation designed to heat us up & increases metabolism about 3-4x resting (whereas metabolism increases about 10x)
Shivering doesn’t have to be in the presence of cold: we shiver when we have a fever too
What is NEAT? energy expended for everything we do that is not sleeping, eating, or sports-like exercise
If you increase the activity of any kind, you increase energy consumption and heat
Examples of NEAT: yardwork, gardening, fidgeting, tapping foot
Some energy drinks tout thermogenic effects which probably make you more jittery and increase NEAT but won’t necessarily improve performance
1. Have a regular bedtime and regular wake up time
2. Don’t use screens within several hours of bedtime
3. Relax! Don’t work right up until bedtime
4. Cool your sleeping environment, making it easier to thermoregulate