Heat Adaptation & Acclimation

Vocabulary flashcards summarizing key terms and definitions related to heat adaptation, acclimation, and physiological responses to exercising in hot environments.

Heat Adaptation

Overall physiological adjustments that enhance cardiovascular stability and heat dissipation during repeated hot-environment exposure.

Heat Acclimation

Short-term (≈9–14 days) heat adaptation from repeated exercise in the heat, yielding lower core temperature, reduced heart rate, and higher work capacity.

Heat Acclimatization

Long-term (months–years) natural heat adaptation achieved by living and training in a hot climate.

Plasma Volume Expansion

First 1–3 day response to heat acclimation in which proteins re-enter blood via lymph, drawing fluid into circulation and temporarily boosting plasma volume to support stroke volume and cardiac output.

Diluted Sweat

Sweat with lower sodium concentration produced after acclimation, helping conserve body salt while enhancing heat loss.

Eccrine Gland Sensitivity

Increased responsiveness of skin sweat glands to aldosterone following acclimation, leading to earlier onset and greater volume of dilute sweating.

Compensable Heat Stress

Heat load the body can meet; core temperature remains stable while sweat rate rises, especially after acclimation.

Uncompensable Heat Stress

Severe heat load where core temperature climbs; acclimation blunts this rise and further elevates sweating when thermal strain is greatest.

Exercise-Heat Stimulus

Requirement that both physical activity and hot conditions be present to trigger full heat acclimation; exercise in cool air confers only partial tolerance.

Time Course of Acclimation

≈70 % of adaptation occurs within the first 7 days, with full benefits reached in 9–14 days of heat training.

Whole-Body Heat Loss Improvement

≈11 % increase in the body’s ability to dissipate heat after two weeks of acclimation.

Heat Therapy

Passive immersion or rest in hot water/air that mimics some exercise-induced adaptations but cannot fully replace active heat training.