This study assessed the effectiveness of head cooling during exercise in the heat on cognitive performance, either alone or with ice ingestion. Ten healthy males, non-acclimatized to heat, ran (70% V̇O₂peak) for 2×30 min in heat (35 ± 0.9°C, 68.2 ± 6.9% RH). Participants completed 3 trials: 10 min of head cooling during exercise (HC); precooling with crushed ice (7gikg^-1) and head cooling during exercise (MIX); or no-cooling/control (CON). Working memory was assessed using the automated operation span task (OSPAN) and serial seven test (S7). Following MIX, S7 scores were improved compared to CON (12 ± 9.5, p = 0.004, d = 1.42, 0.34-2.28) and HC (4 ± 5.5, p = 0.048, d = 0.45, -0.47 to 1.3) during exercise. Moderate to large effect sizes were recorded for S7 and OSPAN following MIX and HC compared to CON, suggesting a tendency for improved cognitive performance during exercise in heat. Following precooling (MIX), core body temperature (T_c) and forehead temperature (T_h) were lower compared to baseline (-0.75 ± 0.37°C, p < 0.001; -0.31 ± 0.29°C, p = 0.008, respectively) but not in HC or CON (p > 0.05). Thermal sensation (TS) was lower in MIX and HC compared to CON during exercise (p < 0.05). The reduction in T_c, T_h and TS with MIX may have attenuated the effect of heat and subsequently improved working memory during exercise in heat.

• The combination of crushed ice ingestion (precooling) and head cooling cap (percooling) significantly improved cognitive performance (working memory) on endurance exercise in the heat and this effect is attributed to the reduction in reduced core temperature, forehead temperature and thermal sensation.

• Single cooling method during exercise via head cooling cap effective for attenuating impairment of working memory by providing maintenance during endurance exercise in the heat and this associated with reduced forehead temperature and thermal sensation following cooling.

• Decrement in forehead temperature and thermal sensation with head cooling during exercise may benefit cognitive performance although with the absence of core body temperature.