Cooling Strategies for Older Adults in the Heat

NCT06349616 | Completed DMC

• 1 other identifier: STUDY24458
• Study Type: interventional
• Target: 12
• Locations: 1 country
• Sites: 1

Brief Summary

The earth's climate is warming, and the number of heat waves has increased in recent years. At the same time, the number of adults over the age of 65 is growing. Humans sweat and increase blood flow to the skin to cool their body when they get hot. Older adults do not do this as well as young adults. This makes it harder to safely be in warm and/or humid conditions. It is important to learn about cooling strategies for older adults to safely be in warm and/or humid conditions. There is compelling evidence that intermittent hand and forearm cold-water immersion effectively reduces the rise of core temperature during heat stress in older adults. However, it is still unknown if this is an effective cooling strategy for older adults. Furthermore, our laboratory has shown that folic acid supplementation improves blood flow responses in older adults. This may be beneficial to older adults during heat stress.

Conditions

Aging

Keywords

Aging; Thermoregulation; Heat Stress

Outcome Measures

Primary Outcomes (3)

• Core temperature

  Core temperature will be monitored throughout each 2 hour experimental visit.

  A slope of core temperature for each experimental aim is calculated and reported through study completion, an average of 1 year.

• Heart rate

  Heart rate will be monitored continuously throughout each 2 hour experimental visit.

  A slope of heart rate for each experimental aim is calculated and reported through study completion, an average of 1 year.

• Blood Pressure

  Blood pressures will be taken every 10 minutes throughout each 2 hour experimental visit.

  Blood pressure for each experimental aim is recorded and reported through study completion, an average of 1 year.

Secondary Outcomes (2)

• Body Mass

  Baseline immediately before beginning the experimental visit and then once again at the end of the 2 hour experimental visit

• Skin Temperature

  Mean skin temperature for each experimental aim is calculated and reported through study completion, an average of 1 year

Study Arms (2)

Folic acid supplementation

EXPERIMENTAL

5 mg/day folic acid for 6-7 weeks

Other: Intermittent cold-water hand and forearm immersion; Other: No intermittent cold-water hand and forearm immersion

Control

PLACEBO COMPARATOR

Cellulose placebo tablet for 6-7 weeks

Other: Intermittent cold-water hand and forearm immersion; Other: No intermittent cold-water hand and forearm immersion

Interventions

Intermittent cold-water hand and forearm immersion OTHER

Participants will be seated at rest in a hot and humid environment. At 2 time points in the experiment, participants will place their hands and forearms in a bucket of cold tap water for 10 minutes.

Control; Folic acid supplementation

No intermittent cold-water hand and forearm immersion OTHER

Participants will be seated at rest in a hot and humid environment.

Control; Folic acid supplementation

Eligibility Criteria

• Age: 65 Years - 100 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Older Adult (65+)

You may qualify if:

• Adults aged 65 and older
• English proficiency

You may not qualify if:

• Chron's disease, diverticulitis, or similar gastrointestinal disease
• Abnormal resting exercise electrocardiogram (ECG)
• Tobacco use
• High-risk determined by the Atherosclerotic Cardiovascular Disease (CVD) Risk Factor Assessment
• Antiepileptic or antiseizure medications
• Methotrexate

Sponsors & Collaborators

• Penn State University: lead

Study Sites (1)

Noll Laboratory

University Park, Pennsylvania, 16802, United States

Location

MeSH Terms

Conditions

Heat Stress Disorders

Condition Hierarchy (Ancestors)

Wounds and Injuries

Study Officials

• W. Larry Kenney, Ph.D.

  The Pennsylvania State University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor of Kinesiology and Physiology

Model Details: Subjects participate in 4 experiments, 2 for each treatment (folic acid supplementation and placebo). The order of treatment is random.

Study Record Dates

• First Submitted: March 19, 2024
• First Posted: April 5, 2024
• Study Start: May 1, 2024
• Primary Completion: July 21, 2025
• Study Completion: July 21, 2025
• Last Updated: July 24, 2025

Record last verified: 2025-07

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)