Purpose This study aimed to assess the efficacy of different in-play cooling strategies for mitigating heat strain during simulated tennis match-play activity in a hot/humid environment representing the most extreme conditions during the US Open (36°C, 50% relative humidity). Methods On three occasions, nine males completed an intermittent treadmill protocol with an exercise intensity and activity profile simulating a four-set tennis match, with 90-s breaks between odd-numbered games and 120-s breaks between sets, according to International Tennis Federation rules. During breaks, 1) the currently used cooling strategy - an ice-filled damp towel around the neck and a cold-damp towel on the head and thighs (ICE); 2) wetting of arms, neck, face, and lower legs with a sponge in front of an electric fan (FAN wet); or 3) no cooling (CON) were applied. Rectal (T re) and mean skin (T sk) temperature and HR were measured throughout. Thermal sensation and RPE were assessed during breaks. Trials were terminated upon reaching a T re ≥ 39.5°C or volitional exhaustion. Results Seven, five, and one participant completed FAN wet, ICE, and CON, respectively. By end set 1, ΔT re was lower in FAN wet (0.92°C ± 0.15°C) compared with CON (1.09°C ± 0.09°C, P = 0.01), and by end set 2, ΔT re was lower (P < 0.001) in FAN wet (1.55°C ± 0.23°C) and ICE (1.59°C ± 0.17°C) compared with CON (1.99°C ± 0.19°C). Mean RPE (FAN wet = 13.9 ± 2.2, ICE = 13.6 ± 1.8, CON = 16.6 ± 1.8), HR (FAN wet = 163 ± 21, ICE 164 ± 22, CON = 175 ± 19 bpm), T sk (FAN wet = 36.56°C ± 0.69°C, ICE 36.12°C ± 0.44°C, CON = 37.21°C ± 0.42°C), and thermal sensation were lower in FAN wet and ICE (P < 0.05) compared with CON by end set 2. Conclusions The currently recommended ICE strategy successfully mitigates thermal strain during simulated tennis match play in hot/humid conditions. The FAN wet intervention is an equally effective alternative that may be more practical in limited resource settings.