Keeping Up Your Daily Walk in Summer Heat During Cancer Treatment — Why Your Body Handles Heat Differently, and How to Walk Safely

Keeping up a daily walk during treatment can do a lot for your strength and your mood. But when the peak of summer arrives, the same route can leave you unusually tired, dizzy, or short of breath. This is not a lack of willpower — your body's ability to shed heat may simply be working differently than it used to.

Chemotherapy and radiation can make dehydration more likely and can disrupt the way your body cools itself (thermoregulation). Nausea, diarrhea, and a poor appetite drain fluids and electrolytes, which leaves you less able to cope with heat. Some medications can also cause dizziness or changes in blood pressure. As a result, heat that felt trivial when you were well can lead to heat exhaustion, faintness, or falls during treatment.

Timing comes first. Avoid the hottest part of the day (roughly late morning to mid-afternoon) and choose the cooler light of early morning or evening. Shaded paths, indoor hallways, or walking inside a large store or shopping center are all good alternatives.

Sip fluids often, before you feel thirsty. That said, some people need to limit fluids because of kidney or heart conditions, so ask your care team ahead of time how much is right for you. Wear loose, light-colored clothing and a brimmed hat, carry water, and let someone know your route — or better yet, walk with a companion.

If you feel dizzy, break into a cold sweat, or notice a racing heart, nausea, muscle cramps, or a headache, stop right away, rest somewhere cool, and take in fluids. If rest doesn't help, or if you become confused or your skin turns hot and dry as sweating stops, these can be warning signs of heatstroke — seek help without delay. On days that feel like too much, it is perfectly fine to shorten the distance or move gently indoors instead. The goal of a walk is not to set a record, but to come home safely.

This article is general information and is not a substitute for your own medical care. Please discuss the right amount of activity, fluid intake, and the symptoms to watch for with your own healthcare team.