As a public safety provider in Las Vegas we repeatedly heard the phrase, "It is a dry heat." When summer temperatures soar above 100 degree and stay there overnight radiating into the next day, it is common to retreat to a chilled dayroom in the fire station.
Company officers push their crews to pre-hydrate as at any time a vehicle crash or fire during the midday desert heat would tax even the most physically fit firefighters. This is compounded in areas where humidity decreases the efficiency of the turnout ensemble's vapor barrier.
While most rehab efforts focus on what to do after the exertion or during the event, science is now revealing that conditioning with heat may make a firefighter more resilient to the heat stresses of firefighting. In the past, working out, running or doing drills in the heat was seen as reckless and for the "animal crews." The discovery of heat and cold shock proteins has given us a look at how the body adjusts to temperature fluctuations. Heat shock proteins are a family of proteins that are produced by cells in response to exposure to stressful conditions.
They were first described in relation to heat shock by exercise physiology labs. However, they are now known to also be expressed during other stresses including exposure to cold, UV light and during wound healing or tissue remodeling.