ISO/FDIS 25242

• Abstract:

  This document provides an environment test to determine the ability of the smart textiles systems (e.g. electrically heated garment) to withstand rapid changes of ambient temperature. It is applicable to jacket, vest, jumper etc., which is including the electrically operating part.

• Status: Not Published
• ICS: 59.080.80 - Smart textiles
• Technical Committee: ISO/TC 38 - Textiles
• Drafting Committee: ISO/TC 38/WG 32 - Smart textiles
• Current Stage: 5020 - FDIS ballot initiated: 2 months. Proof sent to secretariat
• Start Date: 21-Aug-2026
• Completion Date: 21-Aug-2026

ISO/FDIS 25242 is an ISO document at FDIS stage for testing smart textiles systems under cyclic environmental temperature change. It specifies how to expose products such as electrically heated garments to rapid shifts between high and low ambient temperature, and how to measure run-time before, during, and after the test.

It is aimed at products that include the electrically operating part, so it helps manufacturers, test laboratories, and buyers check whether a smart textile system keeps working after temperature cycling.

What does ISO/FDIS 25242 specify?

ISO/FDIS 25242 specifies an environmental test method for smart textiles systems that need to withstand rapid changes of ambient temperature. The document is limited to jacket, vest, jumper and similar items that include the electrically operating part.

The document is organized into scope, normative references, terms and definitions, test equipment, general requirements, test procedure, and test report. In practice, that means it tells the user what to test, what chamber to use, how to prepare the specimen, how to run the cycles, and what to record.

What are the key requirements of ISO/FDIS 25242?

ISO/FDIS 25242 sets out a temperature-change test with defined chamber conditions, specimen preparation, repeated run-time measurements, and reporting. The most important points are below.

Test equipment and chamber conditions

The test uses an environmental chamber in accordance with IEC 60068-2-14 test Na or Nc. The chamber must be large enough for the specimen, allow measurement during conditioning, and hold the specified temperature within the required tolerances.

In practice, this means the laboratory needs a chamber that can actually support the test method, not just reach the target temperatures.

Test specimen and general preparation

The specimen is tested unpacked, switched off, and ready for use, unless the operating conditions specify otherwise. Three test specimens per sample are tested, and all parts needed for connection are available.

This matters because the result should reflect the product as it is normally used, with the correct accessories and operating instructions.

Conditioning and initial run-time

Before cycling, the specimen and chamber are brought to standard atmosphere conditions in accordance with ISO 139. The specimen is then visually examined and electrically checked as required, set to maximum performance conditions, and its initial run-time is measured.

That gives a baseline for comparing how the product behaves before and after thermal stress.

Cyclic temperature exposure

The specimen is exposed to alternating high and low temperatures with defined transfer times, following IEC 60068-2-14 test Na or Nc. The document states that test Na is in air or gas, while test Nc is in water or liquid and applies only to sealed or water-insensitive samples.

This choice matters because immersion can change the result, so the test type must match the product design.

In-operation and finished run-time

During cycling, the run-time is measured for the three specimens and the average is recorded. After the cycle, the specimen is recovered for at least 24 h in standard atmosphere conditions, then visually and electrically checked again and the finished run-time is measured.

For users, this shows whether the product still operates normally after repeated temperature changes and whether any degradation is visible or electrical.

Rate of change and reporting

The document provides a formula for the run-time change rate based on initial and finished run-time. The test report then records the test type, specimen identification, chamber conditions, mounting details, temperatures, number of cycles, measurements, recovery, deviations, unusual features, and the test date.

That gives a traceable record for product comparison, qualification, and supplier documentation.

What terms does ISO/FDIS 25242 define?

• Smart textile system - A fabric that gives an intended response to environmental changes or an external signal.
• Initial run-time (t_initial) - The time from starting the system with a fully charged auxiliary battery until battery discharge stops the system.
• In operation run-time (t_in operation) - The same kind of run-time measured during testing while the specimen is under the cyclic temperature procedure.
• Finished run-time (t_final) - The run-time measured after the test has been conducted.
• Test cycle - One pass from laboratory ambient to the first conditioning temperature, then to the second conditioning temperature, and back to ambient.

Who uses ISO/FDIS 25242?

ISO/FDIS 25242 is used by organizations that design, make, test, or buy smart textiles systems. Typical users include textile manufacturers, electrical garment developers, test laboratories, quality teams, and procurement staff who need a repeatable way to check durability after temperature cycling.

It is especially relevant for electrically heated garments and similar products where the electrical function must still work after storage, transport, installation, and use in changing climates.

Which standards are used with ISO/FDIS 25242?

• ISO 139 - Provides the standard atmosphere conditions used for conditioning and recovery.
• IEC 60068-2-14:2023 - Provides the environmental test chamber method used for test Na and test Nc, including the temperature-change procedure.
• ISO/TR 23383:2020 - Supplies the source definition used for the term smart textile system.

What does the ISO/FDIS 25242 document contain?

ISO/FDIS 25242 contains the full test sequence from specimen preparation to final reporting. It includes the chamber requirements, the cycle setup, the conditioning and recovery steps, and the run-time measurements made before, during, and after testing.

It also includes Table 1 for the Na and Nc test parameters, Figure 1 for the test cycle, and Formula 1 for the run-time change rate. These parts are used for testing and reporting, not for product design alone.

The test report clause lists the information to record, including the specimen identity, mounting, temperatures, exposure duration, number of cycles, measurements, deviations, and unusual observations.

FINAL DRAFT
International
Standard
ISO/TC 38
Textiles — Smart textiles
Secretariat: SAC
systems — Test method for cyclic
Voting begins on:
environmental temperature change
2026-08-21
Textiles — Systèmes textiles intelligents — Méthode d'essai de
Voting terminates on:
changement cyclique de la température de l'environnement
2026-10-16
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
Reference number
FINAL DRAFT
International
Standard
ISO/TC 38
Textiles — Smart textiles
Secretariat: SAC
systems — Test method for cyclic
Voting begins on:
environmental temperature change
Textiles — Systèmes textiles intelligents — Méthode d'essai de
Voting terminates on:
changement cyclique de la température de l'environnement
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
© ISO 2026
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Test equipment . 2
5 General requirements . 2
6 Test procedure . 2
6.1 General .2
6.2 Guidance for the selection of the kind of test .2
6.3 Sampling and preparation of test specimen .2
6.4 Preparation of the chamber .3
6.5 Mounting or supporting of the test specimen .3
6.6 Conditioning.3
6.7 Initial run-time measurement .3
6.8 Test cycle .3
6.9 In operation run-time measurement .4
6.10 Recovery .4
6.11 Finished run-time measurement.4
6.12 Rate of change .4
7 Test report . 4
Bibliography . 6

iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was pr
...

ISO/DIS FDIS 25242:2026(en)
ISO/TC 38/WG 32
Secretariat: SAC
Date: 2026-08-07-20
Textiles — Smart textiles systems — Test method for cyclic
environmental temperature change
Textiles — Systèmes textiles intelligents — Méthode d'essai de changement cyclique de la température de
l'environnement
FDIS stage
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication
may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying,
or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO
at the address below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
EmailE-mail: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Test equipment . 2
5 General requirements . 2
6 Test procedure . 2
6.1 General. 2
6.2 Guidance for the selection of the kind of test . 2
6.3 Sampling and preparation of test specimen . 2
6.4 Preparation of the chamber . 3
6.5 Mounting or supporting of the test specimen . 3
6.6 Conditioning . 3
6.7 Initial run-time measurement . 3
6.8 Test cycle . 3
6.9 In operation run-time measurement . 4
6.10 Recovery . 5
6.11 Finished run-time measurement . 5
6.12 Rate of change . 5
7 Test report . 5
Bibliography . 7

iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of
ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Field Code Changed
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s)
which may be required to implement this document. However, implementers are cautioned that this may not
represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
Field Code Changed
This document was prepared by Technical Committee ISO/TC 38, Textiles.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
Introduction
During their use, e-textiles (smart textiles) can experience to extreme cold environments so durability is a
critical property.
A change of temperature test is intended to determine the effect on the specimen of a change of temperature
or a succession of changes of temperature.
This document specifies the test method and assessment of their performance under conditions of storage,
transportation, installation and use.
v
Textiles — Smart textiles systems — Test method for cyclic
environmental temperature change
1 Scope
This document provides an environment test to determine the ability of smart textiles (e.g. electrically heated
garment) to withstand rapid changes of ambient temperature.
This document is applicable to jacket, vest, jumper, etc., which includes the electrically operating part.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content consti
...