From the description you have provided, it is fairly obvious that this is a reaction to the type pf climate in the place you are living. When the external temperature becomes very high, the body can often break out in rashes like the one you have described. In all likelihood, this is a heat rash and must also be treated thus. You will need to make a few small changes in your diet so that your internal body temperature remains low and does not bother you too much. The first thing to do is to stop eating foods that are considered to be “heat causing”. Typically, this would include all kinds of meat, eggs and most spices. If these are a part of your regular diet, then they would need to be stopped for a while. Make this change and see if it reflects by the disappearance of rashes. Simultaneously, you can also start eating foods that are considered to be instrumental in “lowering” your internal body temperature. These would be a lot of fresh greens, citrus fruits and green vegetables. Pay special attention to cucumber, tomatoes, squashes of all kinds and citrus fruits such as oranges, sweet limes and all kinds of melons. Water melons, in particular, are very useful in cooling the body so much so that the nature of the body changes a great deal.
Meanwhile, you can also start applying things to your rashes which may be helpful in sanitizing them as well as reducing the swelling and redness. For instance, you can apply a paste made with sandalwood and rose water on your rashes in order to help reduce the redness. Applying fresh yogurt to which a few drops of lime juice has been added will also help a lot with sanitizing the rash infected area. You could also rinse your rashes out with diluted hydrogen peroxide. Make sure you dilute it, adding a part of hydrogen peroxide to three parts of water for a better and gentler effect. It is believed that a solution of boric acid powder can also be useful in healing all kinds of external skin conditions. But you would need to try this out on the inside of your elbow and wait for 24 hours. This is known as an allergy test and it is better to see if you are allergic to a strong substance before using it on an affected area. If you are unaffected, go ahead and use it on your rashes.