Recruiting

Observational Study

Sponsor:

Arizona State University

Code:

NCT07654270

Conditions

Mental Acuity

Eligibility Criteria

Sex: Female

Age: 18 - 30

Healthy Volunteers: Accepted

Interventions

water

Study Details

Brief summary:

Heart rate variability (HRV) is a key indicator of fitness, and stress resilience. Previous research has shown that HRV decreases under mental workload, including during tasks that require strict attention. Studies also show that temperature exposure affects attention: cold increases the stress response while warm water has a calming effect. Very few studies combine thermal exposure with cognitive testing, and no controlled trials have investigated whether water temperature modulates HRV responses specifically during cognitive demand.

Conditions

Mental Acuity

Study ID

NCT07654270

Start date

Jul 13, 2026

Status verified date

Nov, 2026

Completion date

Jun 15, 2027

Anticipated

Primary completion date

Dec 15, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: Female

Age: 18 - 30

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Healthy women free of chronic disease (by self-report)
  • 18-30 years of age

Exclusion Criteria:

  • medication/drug use that has not been consistent for the previous 3 months or will be discontinued during the trial
  • any acute illness
  • regular use of cigarettes or marijuana
  • pregnant or lactating women
  • not fluent in English
  • not willing to attend two in-person lab visits in downtown Phoenix and follow study protocol (including abstaining from caffeine in the 12 hours prior to testing)
  • not currently competing in sports or unusually high-intensity exercise protocols (e.g., high-intensity exercise greater than 30 minutes most days of the week)

Study Design

Enrollment

30 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Warm water

Water will be heated to \~55º C (131 ºF)

placebo comparator: Cold water

Cold water: 4-6º C (41ºF)

Interventions

water

water temperature

Primary outcome measure

  • heart rate variability [ Time Frame: 3 minutes ]
  • cognitive performance [ Time Frame: 3 minutes ]

Central Contacts and Locations

Central contacts

Carol Johnston

6024963463carol.johnston@asu.edu

Locations

Health North ASU Downtown Campus

Recruiting

Phoenix, Arizona, United States, 85004

Contacts

Carol Johnston

6024962539carol.johnston@asu.edu

More Information

Sponsor

Arizona State University

Last update posted

Nov 6, 2026

Last verified

Nov, 2026

Keywords

  • heart rate variability
  • water temperature
  • cognitive performance

Trial information was received from ClinicalTrials.gov and was last updated on 2026-11-07. This information was provided to ClinicalTrials.gov by Arizona State University on 2026-11-06. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.