There are many ways your child may suffer discomfort and unless you are well trained or have garnered enough experience you may never know this. Heat rash is one of the common things that cause great discomfort for children. It starts with the sudden development of bright red pimply rash on some parts of the body such as near edges of nappy or underwear, under the arms and on the neck. If you ever observe rashes in any of these places, rather than panic you can be comforted by verifying that it is only rashes. Heat rash or prickly heat as it is sometimes called occurs as red pimply skin eruption is a development you may observe on your child if he overheats under a humid or hot weather.