<s>[INST] Why is cold weather bad for people with high blood pressure? [/INST] It is true that more people have heart attacks or strokes in the winter than in the summer. Cold temperatures make your blood vessels constrict, which helps to conserve heat and maintain body temperature. It also means that there is less room for your blood to flow through, raising your blood pressure and heart rate, and thickening the blood as well.If you already have narrowed arteries due to atherosclerosis, where fat builds up in the artery walls, these changes can cause chest pains (angina) and raise the chances of blood clots forming in the arteries, leading to a heart attack or stroke. The risk of these happening is higher if you have high blood pressure. Source: Blood Pressure UK. Link: https://www.bloodpressureuk.org/resources/frequently-asked-questions/#d.en.819875. Field: Cardiovascular. Disease: Hypertension </s>