Core temperature affects scalp skin temperature during scalp cooling.

BACKGROUND: The efficacy of hair loss prevention by scalp cooling to prevent chemotherapy induced hair loss has been shown to be related to scalp skin temperature. Scalp skin temperature, however, is dependent not only on local cooling but also on the thermal status of the body. OBJECTIVES: This study was conducted to investigate the effect of body temperature on scalp skin temperature. METHODS: We conducted experiments in which 13 healthy subjects consumed ice slurry to lower body temperature for 15 minutes after the start of scalp cooling and then performed two 12-minute cycle exercise sessions to increase body core temperature. Esophageal temperature (Tes ), rectal temperature (Tre ), mean skin temperature (eight locations, Tskin ), and mean scalp temperature (five locations, Tscalp ) were recorded. RESULTS: During the initial 10 minutes of scalp cooling, Tscalp decreased by >15 °C, whereas Tes decreased by 0.2 °C. After ice slurry ingestion, Tes , Tre , and Tskin were 35.8, 36.5, and 31.3 °C, respectively, and increased after exercise to 36.3, 37.3, and 33.0 °C, respectively. Tscalp was significantly correlated to Tes (r = 0.39, P < 0.01): an increase of 1 °C in Tes corresponded to an increase of 1.6 °C in Tscalp . CONCLUSIONS: Slight cooling of patients with an elevated body temperature during scalp cooling contributes to the decrease in scalp temperature and may improve the prevention of hair loss. This may be useful if the desired decrease of scalp temperature cannot be obtained by scalp cooling systems.

Effect of warm-up and precooling on pacing during a 15-km cycling time trial in the heat.

PURPOSE: The best way to apply precooling for endurance exercise in the heat is still unclear. The authors analyzed the effect of different preparation regimens on pacing during a 15-km cycling time trial in the heat. METHODS: Ten male subjects completed four 15-km time trials (30°C), preceded by different preparation regimes: 10 min cycling (WARM-UP), 30 min scalp cooling of which 10 min was cycling (SC+WARM-UP), ice-slurry ingestion (ICE), and ice slurry ingestion + 30 min scalp cooling (SC+ICE). RESULTS: No differences were observed in finish time and mean power output, although power output was lower for WARM-UP than for SC+ICE during km 13-14 (17 ± 16 and 19 ± 14 W, respectively) and for ICE during km 13 (16 ± 16 W). Rectal temperature at the start of the time trial was lower for both ICE conditions (~36.7°C) than both WARMUP conditions (~37.1°C) and remained lower during the first part of the trial. Skin temperature and thermal sensation were lower at the start for SC+ICE. CONCLUSIONS: The preparation regimen providing the lowest body-heat content and sensation of coolness at the start (SC+ICE) was most beneficial for pacing during the latter stages of the time trial, although overall performance did not differ.