Table 3.
Laboratory cold water immersion studies.
| Authors/Pubmed ID |
Study Protocol: Environmental Temperature (Time of Exposure)/Subject Temperature in Cold | Number of Participants (Gender)/Mean Age of Participants (Mean ± SD)/Clothes/Immersion of Whole Body or Part | Timing of Cognitive Test Administration/Duration of Test Battery | Test Battery: Type of Cognitive Test (Cognitive Domain) | Changes in Cognitive Performance (Based on Significant Results, p < 0.05) |
|---|---|---|---|---|---|
| Jones et al. 2019 [8] 31047884 |
7 consecutive (staggered by 24 h) cold water immersion periods at 10 °C (90 min)/Tco (ingestible pill) (~−1.4 °C) and Tsk (~−0.8 to 1.5 °C) | 12 (8 M)/26 ± 5 y/ Bathing suit/ Mid-sternum immersion and upright sitting position and leg extended (right arm outside) |
Before (25 °C) and during immersion (10 °C) at 5, 30, 60 and 90 min/2 min double-digit addition task; PVT-NA | Double digit addition task (WM); PVT (attention) | Decrease in both WM and attention performances. After repeated immersion, an improvement in WM |
| Solianik et al. 2015 [26] 25962329 |
Intermittent cold water immersion at 14 °C (multiple 20 min of cooling followed by 10 min of rest at 22 °C until Tre reduction to 35.5 °C or 120 min of immersion time)/Tre (−1.1 °C in males and −1.0 in females) and Tsk (−13.7 °C in males and 11.7 °C in females) | 27 (14 M)/M 20.6 ± 0.3 y; F 21.0 ± 0.5 y/ Bathing suit/ Semi-recumbent position up to the level of manubrium |
Before (22 °C) and 5 min after the end of the cooling procedure (14 °C)/NA | Free-recall test (memory); forced-choice recognition memory test (visual recognition memory) | Reduced outcome measures on both memory tests only in M related to body cooling |
| Solianik et al. 2014 [25] 25172303 |
Intermittent cold water immersion at 14 °C (multiple 20 min of cooling followed by 10 min of rest at 22 °C until Tre reduction to 35.5 °C or 120 min of immersion time)/ Tre (−0.99 ± 0.52 in males and −0.91 ± 0.55 °C in females) and Tsk (−13.53 ± 1.55 in males and −11.91 ± 3.33 °C in females) |
32 (18 M)/M 20.7 ± 1.0; F 21.4 ± 2.5/ Bathing suit/ Semi-recumbent position up to the level of manubrium |
Before (22 °C) and 5 min after the end of the cooling procedure (14 °C)/NA | Odd/even test (cognitive flexibility/EF), forward digit-span (STM); forced choice recognition memory (visual recognition memory) |
Impaired cognitive flexibility (both M and F); impaired visual recognition and forward digit span in M |
| Brazaitis et al. 2014 [27] 25275647 |
Intermittent cold water immersion at 14 °C (multiple 20 min of cooling followed by 10 min of rest at 22 °C until Tre reduction to 35.5 °C or 120 min of immersion time)/ Tre (FC: −1.5 °C; SC2: −0.9 °C) Tsk (FC: 13.1 ± 1.8 °C; SC2: 13.7 ± 1.5 °C) |
40 (M); 20 FC group and 20 SC2 group / FC 21.2 ± 1.1 y; SC2 22.3 ± 1.7 y/ T-shirt, swim shorts and socks/ Semi-recumbent position with head-out, arms folded across the chest and with legs straight together |
Before (22 °C) and 5 min after the end of the cooling procedure (14 °C)/~10 min | Odd/even test (cognitive flexibility/EF); forward digit-span task (STM); forced-choice recognition memory test (visual recognition memory) | Impaired cognitive flexibility; no significant difference between the FC and SC2 groups in all the CT |
| Seo et al. 2013 [28] 24024303 |
Water tank immersion at 13 ± 1 °C (60 min) or 35 ±1 °C (60 min)/Tsk (Δ −5.8 ± 0.7 °C) and Tre (Δ −0.45 ± 0.2 °C) | 9 (M)/23 ± 2 y/ Swimming trunks and a long-sleeved tight-fitting shirt/ Water level up to the iliac crest in a sitting position |
Baseline and at 10, 30 and 50 min during cold immersion and 12 min after immersion/~10 min | Stroop Color Word test (SCWT; attention/EF) | Impaired SCWT after 13 °C-water immersion |
| Payne & Cheung, 2007 [29] 17679565 |
3 sessions with immersion period up to 36 °C Tco at 15° (CC) or 35° (CON) or (SC1); after immersion in warm water bath (40 °C) at CC and CON conditions and in SC1 seated with only leg immersed in cold water (10 °C)/ Tes was lower during immersion, post-immersion and CT in CC compared with CON and SC1 while Tsk was lower in CC during immersion but not during CT compared to SC1 |
12 (M)/23.8 ± 4.5 y/ Clothes:NA/ Immersion up to the neck |
After immersion and after ~3 min of either 40 °C or 10 °C-only leg exposure/~10 min | Virtual Hebbs–Williams Mazes (HWM; visuo-spatial abilities/spatial learning) Purdue pegboard (manual dexterity) |
No effect on visuospatial abilities (time to completion and mean error scores) in CC and SC1 sessions Effect on manual dexterity |
| Mahoney et al. 2007 [30] 17585971 |
10 °C (2 session of 90 min water pool immersion with rewarming period between) adjusted for each participant to induce a Tco drop to 35 °C vs. 35 °C (control condition)/ Tre (~−1.8 °C) and Tsk (~−12 °C) |
19 (M+F; not specified)/ 20.5 ± 2.5 y/ Clothes: NA/ Seated and water immersion to the chest (stirred water) |
Baseline CT, between the 2 cold (90 min) immersion periods and immediately after immersion/~40 min | Visual vigilance and 4 choice visual RT (sustained attention); delayed match-to-sample (DMTS: WM) | 4 choice reaction time: increased errors and longer RT, match to sample test more errors on delayed paradigm (16 s) |
| O’Brien et al. 2007 [7] 17078981 |
Water immersion at 10 °C (adjusted for each participant to induce a Tco drop to 35 °C within 90 min) then rewarming until Tco returns to initial value and then another 90 min in cold water vs. control condition 35 °C/in cold water Tre (−1.5 °C) and Tsk (−11.6 °C) | 15 (14 M)/20 ± 2 y/ Clothes: NA/ Chest-deep (arms not immersed) water immersion |
After each cooling period and exposure to additional 40 min at 19 °C air tests were performed in a cold room (10 °C)/25 min | U.S. Special Operations Command (SOCOM) subtests: match to sample (WM); visual vigilance and complex RT (4 choice) (sustained attention), serial addition/subtraction (attention and WM), logical reasoning, repeated acquisition (memory) |
Less correct answers on the match-to-sample, slower response time in addition/subtraction improved response time on vigilance test |
| Lockhart et al. 2005 [11] 16235879 |
3 conditions (PDF 1 or 2 or drysuit) in 10 °C stirred water bath (up to 65 min or until core Tes 34 °C)/ Tes at 65 min (drysuit: −0.4 ± 0.2 °C; PDF1: −1.5 ± 0.7 °C; PDF2: −2.8 ± 1.6 °C) |
6 (M)/26.8 ± 6 y/ Swimsuit + drysuit or personal flotation device (PFD)/ Drysuit: horizontal positioned with the back of head and chest immersed in the water; PDF 1: semi-recumbent position with head and upper chest outside the water (head-out); PDF 2: horizontal positioned (recumbent position) with the back of head and chest immersed in the water (head-in) |
Baseline, immediately after water entry and after 50 min of immersion/ ~15 min | Logic reasoning test; SCWT (selective attention/EF); digit symbol coding (attention/speed of processing), backward digit span (WM); paced auditory serial addition test (PASAT; auditory attention) |
Increased time to complete SCWT and decreased number of correct responses for digit symbol coding, backward digit span, and the third set of the PASAT with Tes decrease |
| Baddley et al. 1975 [9] 1205478 |
Water tank immersion at 4.7 °C (4.4–5.6) vs. 25.8 °C (23.3–26.7) (1 h)/Tre (mean change/drop of 0.72 °C) |
14 (NA)/ 23 (range 19–38) y/ Full neoprene wetsuits, bootees, and gloves/Whole body Whole body immersion at a depth of −4.88 m |
At the beginning (during) and after each diving/35 to 50 min | Reasoning test; memory test; vigilance test (attention) | Impairment on memory; no effect on reasoning and attention |
ACE: acute cold exposure; CC: core cooling; CON: immersion period for control; CT: cognitive test; DMTS: delayed match-to-sample; EF: executive function; FC: fast cooling; F: female; M: male; HWM: Hebbs–Williams Mazes; NA: not available; PASAT: paced auditory serial addition task; PDF: personal flotation device; PVT: psychomotor vigilance task; RT: reaction time; SC1: superficial cooling; SC2: slow cooling; SCWT: Stroop Color Word test; SD, standard deviation; STM: short-term memory; T: temperature; Tco: core body temperature; Tre: rectal temperature; Tsk: skin temperature; Tes: oesophageal temperature; SOCOM: U.S. Special Operations Command; WM: working memory; y: years.