The Heat Laboratory

We are Sydney’s first and only heat acclimation service. While this service is primarily for athletes, it is also for anyone who is keen to change up their endurance training or looking for a new challenge that can improve their physiology.

Heat acclimation can:

  • Increase VO2max by 5% in the cool and 8% in the heat
  • Improve time-trial performance by 6% in the cool and by 8% in the heat
  • Power output at lactate threshold 2 (LT2) by 5% in the cool and by 5% in the heat
  • Maximal cardiac output in cool and hot conditions 9% and 5%

Heat acclimation is equally effective for men and women (Lorenzo, JAP 2010, Lundby, JAP, 2023).

Triathlon Athlete Riding Bike

Performance benefits of heat acclimation

Elite athletes have been using heat acclimation for years to great effect and have been traditionally reserved for those professional athletes. At The Heat Lab, we want this to change. The figure below plots the time course of the various physiological measures that we expect to change with acclimation.

Heat acclimation is a series of physiological changes that develop as defensive adaptations to protect ourselves from heat stress.

We can all feel that performance decreases in a hot environment. This occurs because:

  • We sweat more,
  • Dehydrate faster,
  • Core body temperature can rise more rapidly.

These factors can reduce power output, slow run times, increase muscle cramps, and lead to exertional heat illness.

Our goal is to give you a substantial performance advantage over your unacclimated competition.

Products and prices

Base Heat Acclimation Package (4 Sessions)

With this package, we expect moderate adaptations in:

  • Resting heart rate (lowers)
  • Exercise capacity (increases)
  • Thermal comfort (improves)
  • Blood plasma volume (expands)

  • $300 for 60 minute exposures
  • $400 for 90 minute exposures

Moderate Heat Acclimation Package (6 Sessions)

With this package, we expect fully-developed adaptations in:

  • Resting heart rate (lowered)
  • Blood plasma volume (increases)
  • Skin temperature (lowers)
  • Thermal comfort (improves)

We expect moderate adaptations in:

  • Exercise capacity (increases)
  • Resting and exercise core temperature (lowers)
  • Sweat rate (increases)

  • $450 for 60-minute exposures
  • $600 for 90-minute exposures

Fully Heat Acclimation Package (12 Sessions)

With this package we expect all parameters to be fully-developed:

  • Resting heart rate (lowers)
  • Blood plasma volume (expands)
  • Skin temperature (reduces)
  • Thermal comfort (improves)
  • Exercise capacity (increases)
  • Resting and exercise core temperature (lowers)
  • Sweat rate (onset of sweating occurs sooner and at a faster rate, total output increases)

  • $850 for 60 minute exposures
  • $1150 for 90 minute exposures





90 minutes



90 minutes






60 minutes



60 minutes


The following data is collected and reported back to the client/athlete:

  • Whole-body sweat rate (WBSR)
  • Resting heart rate (HR, bpm)
  • Exercising heart rate (HR, bpm)
  • Resting blood pressure (BP, mmHg)
  • Mechanical power output (PO, Watts)
  • Power output for a given heart rate
  • Non-invasive core body temperature (T, ºC)


the lab

Lindsey Hunt, BApplSci (Ex & Spt Sci), MSc, AES

Lead Physiologist

Lindsey holds a Master of Applied Science (Research) in thermal physiology from the University of Sydney, where he examined how caffeine affects human thermoregulation during exercise in the heat. He is currently completing his PhD at the University of Sydney in the field of thermal physiology.

He has conducted hundreds of exercise and passive heat stress research trials during his masters, PhD and as a research assistant in the environmental chamber at the University of Sydney.

Lindsey has decided to bring that expertise to the wider community with the goal of bringing the latest evidence-based heat acclimation service for both athletes and the wider population who could benefit from the benefits of safe endurance exercise in a hot environment.

Lindsey is an Accredited Exercise Scientist (AES) with Exercise and Sports Science Australia (ESSA).

How we measure body core temperature

Outside of invasive body core temperature sensors, there is no gold standard for measuring it. One of the recent developments in the area of non-invasive core temperature estimation is the CORE body temperature sensor. It uses a series of algorithms to estimate heat storage and heat loss with varying degrees of accuracy, however, its accuracy is enough for exercise heat stress applications, perhaps not scientific research in place of invasive measures just yet.

You may have seen these devices used by professional triathletes such as Kristian Blummenfelt, Gustav Iden and World Tour cycling teams such as Ineos Grenadiers and Lidl Trek.

Purchase a CORE device for yourself at a discount on our store here

Frequently Asked Questions

Question: Who is this for?

Answer: Heat acclimation can be a powerful training stimulus for a wide range of athletes from team sports athletes, such as football players, through to cyclists, runners, and triathletes. Our heat sessions are the most beneficial (but not limited to) for endurance athletes (runners, cyclists, swimmers, triathletes).

Q Do these sessions have to be on consecutive days?

A Current research suggests that consecutive heat stress stimuli are most effective, however, consecutive sessions may not be possible for all individuals. Acclimation sessions can be integrated with your training from once/week up to everyday.

Q What do I have to bring with me to the sessions?

A We recommend bib shorts, socks, cycling shoes, with the addition of a sports bra/base layer for women. Given the heat stimulus, jersey’s/shirts are not required, but you can, of-course, wear one if you prefer. Please bring a towel, 1-2 water bottles, any nutrition you require, a change of clothes, and any exercise tracking device such as a Garmin/Wahoo cycling computer/watch.

Q Can I bring my own bike?

A Yes! We have a Wahoo trainer to set bikes up on. We have a range of cassettes and freehubs to fit all road groupsets. So that we can have the correct set up for you when you arrive, please let us know the details of your current cassette/groupset when booking in.

Q Do I have to bring my own bike to each session?

A Currently, yes. We only offer sessions for clients who can bring their own bikes at the moment. We are planning a purchase of a suitable indoor bike so that you have the choice between bringing your own bike and using our indoor bike.

Question: What data can I access in my report?

Answer: In your physiological report, we provide your improvements tracked across each session. We provide your whole body sweat rate, power output, heart rate, core temperature, rating of perceived exertion, resting heart rate, resting blood pressure.

Q Do I have to cycle, or can I run during the sessions?

A We currently only offer cycling sessions. We are planning to purchase a suitable treadmill soon so that individuals have the choice between cycling and running.

Q What is the difference between purchasing sessions individually or as a package?

A The only difference is that a discount is applied to the total when purchasing a package. As you purchase more session as block, you receive a discount. When purchasing 14 sessions, you get one session free.

Q Do you offer lactate testing?

A At this stage, we do not, however, we are planning to offer lactate testing in the next few months. We plan to integrate lactate testing during our regular acclimation sessions. Heat stress has been shown to increase lactate levels for a given power output, and heat acclimation has been shown to reduce lactate levels for a given power output, possibly contributing to the performance improvements seen with heat acclimation.

Q Can I train that day while completing heat acclimation trials?

A Yes, you are welcome to do double sessions if you require as part of your regular training. However, keep in mind that these sessions will stress your body out more than a normal 60-90 minute workout.

Q What happens if I buy a pack then am unable to attend 1 or more sessions (due to any reason such as sickness, injury etc)?

A All sessions/packages are valid to be used within 12 months from the date of purchase. Please reach out to to discuss your options of rebooking.

Q I already have a training from my coach can this be integrated?

A Please provide us with your coaches details and let me know we will reach out to them to integrate these acclimation sessions with their training plan to best suit your intended goals.

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