Background: Core body temperature increases in hot climates due to exercise workload, disrupting heat gain and loss of balance. The human thermoregulatory system regulates core body temperature through factors such as metabolic heat production, air temperature, humidity, and clothing. The study investigates physiological thermoregulatory responses in semiprofessional athletes during walking and jogging in different climatic conditions.

Methods: A factorial experimental interventional design was used to evaluate different physical activity (low (L)=5 km/h and high (H)=8 km/h) and climatic conditions within the Thermal Environment Laboratory at Lund University, Sweden. The temperature within the climatic chamber was set at 40°C and 31°C, with a relative humidity of 20% and 70%, (hot dry (HD) and hot humid (HW), respectively, to account for a 28°C WBGT. The study used independent T-tests, ANOVA and simple linear regression models to analyse the physiological responses of semiprofessional athletes under different test conditions, comparing gender differences.

Inclusion Criteria:

• Participation at the regional competition level
• Receiving monetary remuneration for their sports engagement
• Participating in sports activities in the previous six years
• Average training experience of 6.0±1.4 years
• A weekly volume of 6.3±0.7 days for 2.3±0.7 hours (h)·day-¹.

Exclusion Criteria:

• A 2 kg weight change in the previous month
• Adherence to special diets
• Use of nutritional supplements
• Smoking
• An acute or chronic communicable or noncommunicable disease
• Heat allergic problems.